Anyone expecting an NBA player to NOT "fight girly" or expecting a player to treat an NBA squabble as an actual fistfight is just setting themself up to look stupid with their "omg he is teh p****" posts.
The players are there to PLAY BASKETBALL. Quite obviously, once things escalate and get physical, the reality of ejections and suspensions enters the minds of NBA players. This restrains them to an extent.
They still want to kick the crap out of the other guy (in this case, out of McDyess for pushing harmless Madsen to the floor just because he plays physical ball), but they realize that there are harsh consequences for anything resembling fighting.