I occasionally collaborate with a colleague who is quite experienced and skilled professional. Though he is so stubborn and intolerant to almost everybody else despite his of her status, authority or responsibility area. For example, when the three of us were negotiating job scope directly with him and our contractor, he, from the very first minute, started to almost dictate things and push his way of looking, ignoring almost every argument the contractor adduced.
From my position now, is quite difficult to exert influence on his behaviour neither directly nor via escalation, since I have worked within the company for significantly shorter period of time. Moreover, I don't even think it is necessary to do so, because a) we're different, and, unless it doesn't spoil our collaboration, let everyone be himself whatever he is; b) changing somebody's character is mostly useless and ungrateful job.
I don't actually want nor being driven to escalate the problem. But I see the situation probably may turn out worse in short time driving many poorly prepared people in a huff, mostly new staff and contractors.
What arguments should I use to deal with the situation, make my coworker be a little patient, without either arguing with and denouncing against him?
A little fact that may be significant is that we work remotely from each other, as well as the contractor does.