Here's what happened at that final turn (and it all happens REALLY FAST):
1) Just as Apolo is starting his move up from fourth, the leader Si-Bak's right (outer) skate sideslips about six inches - this is the precipitating event that will eventually cause his fall. Notice his right hand immediately sweep down to touch the ice very briefly, attempting to restore the balance he is starting to lose.
2) Apolo continues his passing move, his skate pushing Tremblay's left (balance) hand, also putting a hand on Tremblay's hip and wedging into his lane just a little more than the space allows (remember, we're talking about a total surface contact area of a knife blade, and a likewise minimal balance tolerance).
3) Tremblay starts to fall.
4) Si-Bak still has his left hand - the inside hand they usually put down on the turns - on the ice, because he does not have the balance needed to lift it and start skating yet;
5) Hamelin's left hand is already off the ice and he starts his stride coming out of the turn, Si-Bak's hand now in the way of Hamelin's left skate as it comes forward.
6) Si-Bak loses his fight with gravity, his left skate shooting out as his left hand drags across Hamelin's right skate on its forward stride. The difference between this contact and Ohno contacting Tremblay, is that Ohno caused that, while Si-Bak, by falling, is responsible for blocking Hamelin who skates into him.
7) Hamelin flails and somehow maintains balance by translating the torquing of his skates, combined with his forward speed, into a turn that has him facing backward a moment after crossing the finish line.
9) Apolo crosses the line, more who-me than oh-no (sorry; but look at him).
BTW there are several judges involved in making decisions like a DQ, and anyone echoing Apolo's comment: "You know, it's the head Canadian referee out there and there were two Canadians in the race" is only displaying ignorance and bringing shame on themselves
That is what happened, i watched it over and over, at various speeds and frame by frame, because i wanted to know for myself that the jingoistic crap spouted by those of you who sound an awful lot like sore losers, was just that. Somebody even denied Apolo's comment. Lemme tell ya something:
moments after he said it, live, my mom called me from Pittsburgh (Go Steelers!), and asked if I had seen or heard it. She was shocked, because she's a fan and was disappointed that he didn't show more character than to stoop to such a cheap aside. We're Canadians, and proud of it - and you bet we want to win as many medals as we can, we want to win that hockey game on Sunday... but let's be good sports about it all, eh?