I'm not sure what the umps were thinking. If it were anyone other than Pedro, he would have been instantly ejected. Zim too should have been ejected, as should have Ramirez for walking to the mound with a bat in his hand later in the game. But the umps didn't want to get torn apart by the home team crowd (presumably) so they did nothing. Watching Zim get knocked down as he charged Pedro was very disturbing. Pedro showed that he has no class - he's just an impetulant child. Clemens showed his true class.
Funny thing is that I'm rooting for Boston in this one.