I was watching a NASCAR race when one car slid up the turn into another who was moving up on the outside, sending the outside car hard into the wall and out of the race; the inside car, having transferred his excess centripital (centrifugal?) energy to the outside car, regained control, avoided the wall, pitted, changed four tires, and was on his way. The outside driver was in that helmet/gloves/epithet-throwing mode, standing on the tracking and gesturing to the other driver who he thought was #1, or something like that, as the inside driver came around again under the yellow. They get the outside driver on mike before he even gets to the infield hospital, and immediately he accuses the other driver of crashing him out over some previous interaction they'd had. Mike-holder tells him the inside driver had a right rear going down, and every driver knows that when that happens, you're going up the track out of control with no way to stop it -- the outside driver just happened to pick the wrong time to pass. Outside driver then says, "Oh, well then, if that's what happened, I guess that's just racing."
It seems to me that in many situations, we jump to conclusions about the other guy's motive when his actions mess up our day. Perhaps if you set your mind so that when something like this happnes, you first consider the other pilot "inadequately educated" rather than "Bush League," there's a chance for some reasonably professional discussion once you all get on the ground. "Hi, I'm Dave, and I'm the instructor who was in that other plane in the pattern just now. I wonder if I can ask you a question about what happened out there?" Going in with that attitude and that sort of approach can make all the difference between you walking off with a chip on your shoulder and the other guy having his discourtesy reinforced, versus him walking away with a better understanding of "good-neighbor" flying and you feeling that you've accomplished something positive.