I dunno, Joe's posture did come off, to me, as more defensive rather than offensive, like in a position to fend off a punch rather than throw one.While some people block open handed, I could see doing your blocks with closed fists as you may be less likely to break a finger that way.
After all, didn't Willie come running through the house at him? That would put me in a defensive posture.
Now I agree that Joe didn't do anything to defuse the situation and his words could have been designed to set Willie off, but when he basically says he is planning to get himself evicted, and that means violence and he comes running at someone, I don't know how many people would stand in open body beatmewhipmemakemewritebadchecks position and see what kind of violence the guy is going to lead with.
There certainly was plenty of testosterone poisoning to go around with that, and I'm sure Willie was hoping he could take someone out with him.