Just checked the YouTube video.
Stoudamire came onto the court and was walking towards Nash, all before any of the pushing after the foul started.
So how could he be reacting to the pushing?
Until the extra pushing, there was nothing except a hard foul by Robert Horrible - and I bet it wasn't even reported yet. The NBA must have a messed up idea of what an altercation is, because I think it's clear that the altercation is the pushing afterwards.
In fact, when the altercation had started - Stoudamire was already walking back to his bench.
Stern is an idiot. But we all knew that anyways.
http://www.youtube.com/watch?v=lMbHstgkIeE