system
Given the following post, respond as if you're commenting on Reddit:
human
PhD student - Asked to write a letter in support of tenure; mixed feelings about professor

I am an advanced PhD student in a STEM field at a prestigious R1 university. I was asked to write a letter in support of tenure for Professor S. I've been around enough labs to know what is normal and not-normal behavior. 

Professor S brings a lot of money into the university and has a large lab. I worked as a sort of consultant for a year for Professor S's lab because I have a specific skill set he needed. He paid me hourly and also provided some mentorship. He is not my direct adviser. I was considered part of his lab but not really one of his students. His tenure does not affect my career.

Professor S was very helpful to me in many non-trivial ways. I think he genuinely tries really hard to be a good mentor. That being said, working with him was very challenging. Without getting into much detail, I started to really regret not having a contract with him because he kept adding unreasonable requests to my workload that we never agreed upon. He threatened my career when I tried to decline work for him (I was declining a task I had never agreed to do originally). He doesn't take "no" for an answer... He definitely uses emotional manipulation or tries to convince you that what he wants is in your best interest. For an example, he demanded a PhD student skip a big exam for a required class to add the finishing touches to a conference poster that wasn't even due for another week. He totally derailed this student's NSF proposal by making this (frankly trivial) poster the utmost priority. He wanted it done urgently and didn't think the student's class was important.

His PhD students refer to him as a bully. They've all learned to be incredibly blunt and assertive with him. He treats students that work in his lab very disrespectfully when he is anxious or angry. He *yells* at undergrads, coordinators, and PhD students out of frustration. He will also apply unreasonable amounts of pressure to get certain tasks done without understanding the scope of what he is asking (because he's never worked extensively with this type of protocols or equipment himself). Often, due to his pressure to get things done in a truly unreasonable time-frame or without people being properly trained, things don't get done right and resources are wasted. His entire lab is held together with stopgap solutions that end up making more work for everyone in the long-run. 

I would not recommend that future PhD students join his lab. I've personally managed to set boundaries with him but it was a very difficult process and I had to get other faculty members and campus services involved to defend me (which they all did). I am still extricating myself gracefully.

So, my question is, is this the sort of thing the tenure committee cares about? Is it appropriate for me to write a bad letter or perhaps just not write one at all?  I could talk about the good stuff (there is some) but I would also feel obligated to mention the bad. I doubt it will matter since he brings in so much money but maybe it would be useful to have on file? My department pretends to care about students but when push comes to shove they don't. 


TL,DR: Professor I work with is awful. Do I write a bad letter, a weak letter, or no letter at all in support of his tenure?



Edit: I am not sure how relevant it is, but I know that at least one of his PhD students is also declining to write a letter and has already spoken to the head of the tenure committee about it.

Another edit: Technically I was invited by the committee to, "contribute a letter commenting on his candidacy" which is a bit different than being asked to write a letter of recommendation.

FOLLOW UP QUESTION: Could it hurt me somehow if I decline to write a letter (and he knows I was asked?)? Are they kept confidential forever?
gpt
Tenure committees tend to listen to graduate students. They aren't super impactful, but they will listen.

If you have serious concerns, I'd say you should write the letter, talk to your internal graduate student association, and have the society send the letter unsigned. Academia is not like a normal workplace, and things like this can come back and bite you.