To be bang to rights means to have irrefutable proof of wrongdoing, but in this sentence the person manages to come up with a defense
Context: "But on the subject of appearing to own a stolen horse, he still managed to come up with a compelling defense."
Hypothesis: But on the subject of appearing to own a stolen horse, he had rincewind bang to rights and, also, a foot on his neck.
Based on the context, is the hypothesis true, false, or unknown?