In the climatic battle of The Avengers, we see the full might of our heroes teaming up to protect the world.
However, one scene during this battle, while hilarious on it's own right, does not make much sense to me.
While battling the Chitauri together, Thor and Hulk eliminate what appears to be a small force residing in a building. While catching their breath, Hulk all of a sudden punches Thor with great force away from him.
But why does he do this?
The theories swirling in my head point to either a revenge punch for their fight in the Helicarrier. Or a brofist for beating a pack of Chitauri, taken a bit too far.
Is there any official wording on why this happened and Thor seemed to think nothing of it?