I've been watching other videos of the play and a lot of talk has been of KG's hit or tap to the groin of Frye, which obviously didn't really hurt; though that doesn't make it okay.
What seems much worse to me after watching again, is the way KG placed his foot directly under where Frye was going to land, and thus, Frye landed on his foot. This seems much worse and a lot dirtier since it can cause injury.
Apparently, KG did this to him twice and at this second time, along with the hand to the groin, the combination infuriated Frye and that's why he jumped up so fast into KG's face.
I don't like any of our players to play dirty and risk the health of any player because it's just plain sleazy and completely unnecessary when a truly good player does not need to resort to dirty tactics.