How can two people be innocent until proven guilty if their stories conflict? So Bob accuses Alice of stealing his horse. Alice accues Bob of lying slander. They can't both be right. So one is innocent the other is guilty. But according to the law they are both innocent until one is proven guilty. So the law is in conflict with logic. How can this be? Another situation. One of two twins steals a chemical weapon which is caught on CCTV. We know one of the twins is guilty. But in this situation wouldn't the logical thing be to assume both are guilty and send them both to jail in order that the guilty one doesn't activate the chemical weapon?
You misunderstand the significance of the phrase "innocent until proven guilty." This is in part because you are not considering the entire phrase. The full phrase is that an accused party is "presumed innocent until proven guilty." This does not mean that the accused is innocent, only that criminal procedure must take as its starting point that the accused did not commit the crime. The major implication of the presumption, and indeed its original purpose, is that it places the burden of proof on the prosecution. This means that if a prosecutor asserts that you stole something, you do not have to prove that you did not. Rather, the prosecutor must prove that you did. The only reason to present evidence of your own is to rebut the prosecutor's evidence. Another practical implication is that a decision to detain someone awaiting a criminal trial may not be based on the assumption that the accused committed the crime. On the other hand, that decision is not based on the assumption that the accused did not commit the crime. There is a presumption of innocence, but no assumption of innocence, and the government is not obliged before the person is convicted to treat the person as if there is no accusation or charge. Wikipedia has a decent discussion. If we modify your question accordingly, it becomes How can two people be presumed innocent until proven guilty if their stories conflict? Now the answer should be clear. The prosecutor must develop evidence that shows which one of the people has committed the crime. If the prosecutor cannot do that, neither person may be punished.
That's the entire point of a summary proceeding. You're allegedly found committing an offence, that isn't worth the court's time to hear but nevertheless requires some penalty. The only way to "unambiguously deny liability" is by requesting a hearing and denying liability in the notice of this. The court doesn't care what you say to everybody else, it cares what you say on its record. The reasoning is, if you're so sure you're not guilty of an offence, why haven't you sought to argue this in court? And if you weren't committing the offence, why did the informant serve the infringement notice in the first place? The act is not silent at all on this. If you don't request the hearing and serve such notice by the date required, you are liable to enforcement action - whether you deny liability out of court is irrelevant.
We're missing a lot of facts that would help drive the analysis. The first question I'd ask was whether this was part of an actual or attempted sex offense. If that's the case, the suspect could be facing particularly serious charges. Other information is also missing, such as the drug involved, whether it's on the list of controlled substances, her knowledge of the drug, her relationship to the suspect, and so on. Still, based on the information we've got and the inferences we can make from them, I could reasonably see the following charges being filed: Sec. 12-3. Battery. (a) A person commits battery if he or she knowingly without legal justification by any means (1) causes bodily harm to an individual Sec. 12-3.05. Aggravated battery. (g) Offense based on certain conduct. A person commits aggravated battery when, other than by discharge of a firearm, he or she does any of the following: (1) Violates Section 401 of the Illinois Controlled Substances Act by unlawfully delivering a controlled substance to another and any user experiences great bodily harm or permanent disability as a result of the injection, inhalation, or ingestion of any amount of the controlled substance. (2) Knowingly administers to an individual or causes him or her to take, without his or her consent or by threat or deception, and for other than medical purposes, any intoxicating, poisonous, stupefying, narcotic, anesthetic, or controlled substance, or gives to another person any food containing any substance or object intended to cause physical injury if eaten. Sec. 12-4.5. Tampering with food, drugs or cosmetics. (a) A person who knowingly puts any substance capable of causing death or great bodily harm to a human being into any food, drug or cosmetic offered for sale or consumption commits tampering with food, drugs or cosmetics. Sec. 12-5. Reckless conduct. (a) A person commits reckless conduct when he or she, by any means lawful or unlawful, recklessly performs an act or acts that: (1) cause bodily harm to or endanger the safety of another person; or (2) cause great bodily harm or permanent disability or disfigurement to another person. Sec. 21-1. Criminal damage to property. (a) A person commits criminal damage to property when he or she: (1) knowingly damages any property of another Sec. 11-1.20. Criminal sexual assault. (a) A person commits criminal sexual assault if that person commits an act of sexual penetration and: (2) knows that the victim is unable to understand the nature of the act or is unable to give knowing consent; Sec. 11-1.30. Aggravated Criminal Sexual Assault. (a) A person commits aggravated criminal sexual assault if that person commits criminal sexual assault and any of the following aggravating circumstances exist during the commission of the offense or, for purposes of paragraph (7), occur as part of the same course of conduct as the commission of the offense: (2) the person causes bodily harm to the victim, except as provided in paragraph (10); (3) the person acts in a manner that threatens or endangers the life of the victim or any other person; (4) the person commits the criminal sexual assault during the course of committing or attempting to commit any other felony; (7) the person delivers (by injection, inhalation, ingestion, transfer of possession, or any other means) any controlled substance to the victim without the victim's consent or by threat or deception for other than medical purposes; Sec. 11-1.50. Criminal sexual abuse. (a) A person commits criminal sexual abuse if that person: (2) commits an act of sexual conduct and knows that the victim is unable to understand the nature of the act or is unable to give knowing consent. Sec. 11-1.60. Aggravated criminal sexual abuse. (a) A person commits aggravated criminal sexual abuse if that person commits criminal sexual abuse and any of the following aggravating circumstances exist (i) during the commission of the offense or (ii) for purposes of paragraph (7), as part of the same course of conduct as the commission of the offense: (2) the person causes bodily harm to the victim; (5) the person acts in a manner that threatens or endangers the life of the victim or any other person; (6) the person commits the criminal sexual abuse during the course of committing or attempting to commit any other felony; or (7) the person delivers (by injection, inhalation, ingestion, transfer of possession, or any other means) any controlled substance to the victim for other than medical purposes without the victim's consent or by threat or deception. Sec. 9-1. First degree Murder (a) A person who kills an individual without lawful justification commits first degree murder if, in performing the acts which cause the death: (2) he knows that such acts create a strong probability of death or great bodily harm to that individual or another; or (3) he is attempting or committing a forcible felony other than second degree murder. Sec. 9-3. Involuntary Manslaughter and Reckless Homicide. (a) A person who unintentionally kills an individual without lawful justification commits involuntary manslaughter if his acts whether lawful or unlawful which cause the death are such as are likely to cause death or great bodily harm to some individual, and he performs them recklessly Sec. 9-3.3. Drug-induced homicide. (a) A person commits drug-induced homicide when he or she violates Section 401 of the Illinois Controlled Substances Act or Section 55 of the Methamphetamine Control and Community Protection Act by unlawfully delivering a controlled substance to another, and any person's death is caused by the injection, inhalation, absorption, or ingestion of any amount of that controlled substance. Sec. 9-3.4. Concealment of homicidal death. (a) A person commits the offense of concealment of homicidal death when he or she knowingly conceals the death of any other person with knowledge that such other person has died by homicidal means. Sec. 9-3.5. Concealment of death. (b) A person commits the offense of concealment of death when he or she knowingly conceals the death of any other person who died by other than homicidal means.
Is this normal? Pretty much. Witnesses lie in court all the time (in my experience, defendants, law enforcement officers and medical doctors are the most likely to lie). Dealing with a witness who lies in court under oath effectively is one of the most challenging tasks lawyers face. It is an inherently challenging hurdle to proving or defending a case. The facts as presented in court often differ in some material way from reality. It is a pretty tough thing to accurately measure, but my gut estimate would be that this happens in a least 30%-40% of cases that produce contested trials, although not infrequently, a judge or jury will not find the false testimony to be credible. On the other hand, it isn't at all uncommon (probably at least 10% of the time) for a judge or jury to believe the liars to be telling the truth, and to find the people who are telling the truth to be less credible. There is absolute immunity from civil liability for lying in court testimony, although it could, in theory, give rise to contempt of court sanctions from the judge in some circumstances, or to a prosecution for perjury. But, perjury prosecutions are, in practice, very rare, and a good share of them arise from false statements made in documents under oath, rather than from courtroom testimony. There is probably less than 1 perjury prosecution per 1000 provable lies made under oath in courtroom testimony on material issues that end up influencing the outcome in a case. I totally sympathize with how frustrating this situation is having been there in cases that I am litigating many, many times. But, in short, life isn't fair.
Basically, it is up to the court. The relevant law is the Police and Criminal Evidence Act (PACE). You don't give much in the way of specifics, but it sounds like you confessed something to the police at the side of the road immediately after the accident, and now wish to dispute that confession. If you are taken to court and the police want to introduce your confession as evidence then you (through your lawyer) can ask the court to rule it out. You may be able to do so on a number of grounds. Was the confession properly recorded at the time? Were you treated in an oppressive manner, such that you felt you had to say what the police wanted to hear. Did you think you might get more favourable treatment if you said what the police wanted? For instance, did you think you might be allowed to go home once they were satisfied? Were you given a proper rest, or were you in a mental state that might cause you to say things without understanding the consequences (it sounds like this would be your main argument, but consider the others too). [Edit] If you needed medical treatment that would also be relevant. Were you properly cautioned (that speech beginning "You do not have to say anything...") before the police asked you questions. If you think you may be facing criminal charges then you should get yourself a lawyer sooner rather than later. A lawyer will know all about this and be able to navigate the relevant legal processes on your behalf. A bit of background: back in the 1970s the police frequently attributed incriminating statements to suspects when arrested, such as "Its a fair cop, guv", or "Who ratted on us?". The rules in PACE were made to stop such "verballing".
Because in a civil case you have two equally involved sides. If I claim you damaged my car which cost $10,000 to repair, it's not only that you lose $10,000 if you lose the case, but I lose $10,000 if you win the case. Therefore the burden of proof should be equal in both directions. Assume a kid at an expensive boarding school is accused of causing $10,000 damage to the headmaster's car, and instead of suing for damages, the headmaster took the $10,000 out of the kid's school fees and tells the parents that the kid will be thrown out if they don't pay another $10,000. We have the exact same argument, but now the headmaster would be in court and accused. If the burden of proof was "proven beyond reasonable doubt", in the first case the parents would have to pay if it was proven beyond reasonable doubt that the kid was responsible; in the second case they would only get their money back if it was proven beyond reasonable doubt that the kid was not responsible.
In the USA, you must be found guilty "beyond reasonable doubt". As you describe it, I'd say there is an unreasonable suspicion of guilt, not guilt beyond reasonable doubt. If the magician killed three people that way, then three unexplainable deaths following three spells might get him convicted. A jury might say that even though there is no way to explain how the killing worked, the correlation might be enough to prove guilt beyond reasonable doubt.
There are all manner of reasons that evidence can be excluded at a trial, most of which are set forth in rules of evidence. If the evidence was not admitted on the grounds of relevance and the charge was speeding, I presume that the reason that it was found not be to relevant was that it was not possible from a video to determine how fast someone was driving and there was no dispute in the case over who was driving. If the defendant could have articulated some reason that the video was relevant to those points, perhaps it could have been admitted. But, as if often the case, pro se defendants are usually not articulate enough to set forth a legally relevant reason that evidence should be admitted. Unless the defendant could show that the video showed something allowing a jury to determine whether or not the law was violated, it probably wouldn't be relevant and I can't easily imagine how it would be relevant, but perhaps there was some special facts or circumstances that might show, for example, that the speed gun was actually picking up another vehicle.