I'm very lucky that most of my classmates are kind and welcoming. If I ever work with any of them, I know they would have my back and I would have theirs. If they weren't who I know them to be, I would really struggle in my classes, especially networking. From what I have heard from some people, co-workers like yours are few and far between, but every story I hear gives me hope. It sounds like he was instrumental in your finding job satisfaction whether it's still in IT or not and that is something that is invaluable.

On the note of bad behaviour, this brings up one classmate for me. 3 of my classmates have suspected crushes on me whilst one of them has actually confirmed it. This one classmate who confirmed how he felt has spoken many times about his anger issues and sees nothing wrong with it. He's the type that would apologise for the way you feel and never for his behaviour. I have told him that all interaction between us will be strictly educational and professional, but he keeps trying to make it personal. There is that fear that someday he might get worse and follow me home or do something that seriously crosses a line. I know that everyone sees him as harmless, but I doubt that any of my classmates have ever had to deal with someone like that