OK, that's misleading, because the goal itself was pretty awesome. It's a classic case of Arnott being in the right place at the right time. He knew Mike Green's slap shot would be deflected into the corner like that, so he anticipated the whole thing and finished the play. The play tells you everything about what Arnott has added to the team since he was acquired in February.
But the celebration might have been even better.
Here's how Arnott decided to celebrate, via @johnctownsend. Click to play.
Now that is one intense roar. Let's be honest: given how much Arnott has been through in his long NHL career, he was saving a celebration that intense for the playoffs.