I disagree with the justification, but basically they said because Benson went into the crease voluntarily, but then was constrained there by the defender, the fact that he went in on his own is why it was called. Watching the replay it looks like he was in the top of the crease but then actually got his feet out of the crease before the puck went in. Ummm.... I dunno. I thought it was a good goal.
I'm trying not to look back. That's the best I can do.