It's hard to say who's the perp in this one. You watch the replay and it appears that Segal was going for the check but I doubt he had malice on his mind. Why would he take a dumb penalty with his team up by just one goal they had scored only a couple minutes earlier?
I usually am not a big fan of punching when they are down, but when it is a knee on knee, all rules go out the window. I also don't like to see every hit result in someone having to defend himself after a body check, but again it was knee on knee, so I don't blame Regehr one bit. I don't think it was intentional, but when it happens that fast, someone is going to flip as we are talking about season ending injuries.
You can have incidental contact. The puck carrier makes a little move and the Dallas guy starts to pull up then the collide. I say it happened too fast to have a contentious effort to go knee to knee. Go back and look at a Bryan Marchment knee to knee.
Hey boneheads, look at the collision. Both players are turning left when they hit, which will always put your feet across the other's path. Segal was going for the hit, Stajan tried to avoid it by jumping and it's a good thing, probably avoided a knee injury. But it also made it look worse than it was when he went ass over elbows. Neither of these players are dirty players but you just gotta come back after a spectacular-looking hit and stand up for your teammate. Regehr, just on the ice, did that despite his age and did well against someone who would lump him up if Segal wasn't at the end of a long shift. Win to Regehr of course, but there's nothing sinister here. You drama queens need to get a life.