As a BYU fan, I was embarrassed to see some of the late hits, taunting and so many personal fouls. But I don't think you can classify that as dirty. Dirty is when you are trying to injure someone or do something to cheat. This is football. It is an aggressive game. I think there's a delicate balance between being aggressive and knowing when and how to reign it in and hold back. The coaching staff has been erring on the side of letting them be aggressive, but I think after this game, they are going to try to reign it in a little bit. I would prefer to never see taunting and I thought the refs did a decent job of keeping that under control. I could argue that they could have called taunting on the Virginia players in a couple instances, but they let it go.
I agree that the reffing was bad on both sides of the ball, I didn't feel like they had an agenda (unlike refs from a certain conference along the Pacific, with 11 or 12 teams). I was getting frustrated near the end of the game, when it seemed like every other play was a flag on BYU, pretty much marching the Hoos down the field without them having to earn it. Maybe all of those flags were legitimate, I don't know, I'd have to go watch it again, and it still probably doesn't show everything. So I don't think it takes a stretch of imagination to see why all the fans sitting in the stands were getting frustrated with all these calls that they couldn't see happening, whether they did or didn't occur. Is it ever OK to boo refs? I guess that's a separate debate.
Like Rogue Gunner, I would also like to see some of these dirty plays you saw that weren't flagged.