The big question I have reading this is, how does the guy act with more junior students? Is he also being passive aggressive or cranking hard on them? Or giving them 'advice' on techniques? Or is it just seniors that bring out the worst in him?

Because if he's causing problems for the juniors or pushing them around I'd be way more concerned about that -- for the senior students it's frustrating but just doesn't have the same degree of impact or possible harm. They're far more able to take care of themselves. If anything if someone's 'difficult' I would think the seniors should try to step up so the juniors don't have to be the ones dealing with him. (Though yeah, if that has to happen for a long time that's kind of a problem).

As far as practicing with him personally, without knowing the guy so take that for what it's worth, my instinct is that I'd just try not to worry about whether he's learning anything. Let that be his problem. I wouldn't correct him at all, even if he did a totally different technique, I'd just take ukemi as well as I could when it was my turn to take ukemi, ask him to go easier on the pins if he's cranking them on, and just do my best as nage and accept that it's not going to be the best practice. If possible I'd try to find something I could work on for myself when practicing with him, maybe the beginning or middle of the technique if he tends to anticipate the end, or even just my own posture or footwork. If he's determined not to learn anything, that's his problem. I really don't see the point or benefit of 'helping' someone unless they actually want your help.

I'd also go slowly when working with him and try in particular to do pins and throws slowly and relatively gently. Partly because he sounds like he maybe needs and wants people to go easy on him (even if he's not good at saying so directly), and partly to set a good example for him (the last thing you want is for him to feel hurt or afraid and for him to try to do it harder on you to 'show you what it feels like').