I'm not saying this as a complaint, but I really wondered at the time whether the goal would count. Any time I've ever seen this happen, the offensive player was shooting while a goalie or defenseman knocks the post off, and the puck goes directly in.
This was a little odd in that Dobson was sliding across the crease to block the shot, and in fact he did block the shot and knocked the post off in doing so. The puck then ricocheted off Dobson and then off Sorokin and then across the goal line (between where the posts used to be). And if that's the call that's fine. However, it does set the precedent that ricochets will count as goals in the future. While this was a very fast, bang-bang thing, the duration of the sequence of events should not matter in the future so long as the offensive player was in the act of shooting when the post came off.
So, for a more extreme example, if a goalie knocks a post off in pushing off to go across the net and the puck bounces off his waffle and 30 feet straight up in the air, and then comes down and bounces off a defending teammate and across the goal line between where the posts were, that also needs to be a goal.