I feel bad for Perron because he doesn't see it coming but Jesus Christ he has the puck come to him and he's moving forward. Of course it's af****** blind side hit because PERRON ISf****** LOOKING BACKWARDS AT THE PASSER while moving forward. This is an utterly stupid call, Thornton's elbows are not his shoulders, which is what actually makes contact, he follows through with his elbow coming upward after the hit (last time I checked following through with your elbow moving upward doesn't constitute an elbow when the elbow doesn't even make contact -- the elbow moving up is merely an affect of balancing one's self from the jolt of hitting someone with your shoulder), and yes, this is marginalizing clean hits just because a guy gets hurt. Unbelievable.
Edit: I also have a feeling of deja vu because I remember off the top of my head Jiri Hudler being hit many times looking the wrong way.
Agreed. 1) This is shoulder not elbow. 2) most of this is a result of Thorton being a big guy and the angle that they met. 3) Thorton did not intend to injure. If you look closely, he doesn't come close to leaving his feet and does not in any way "drive" into Parron. Tough break for David, but mostly his fault.