When you lean too far to the left to reach a text book, you go a falling to the ground. Or you collide with someone sitting next to you. And that's probably what Vani had in mind here.
While Scott didn't expect this, he's used to accidental and occasionally violent collisions being the awesome klutz that he is. And one klutz deserves another.
You can catch Betsy on twitter where she is more active, https://twitter.com/betsythebeaver