hey it actually was in the manga
i thought at first it's just as confusing as the anime
then i remember reading this bit before and thinking it was confusing
but then i figured it out...

Ok this is what happened:
-There was the explosion (shown)
-Naruto and Neji flew out of the explosion cloud (not shown)
-they hit the ground and made their own hole and made a dust cloud while doing so!!!

Note that the cloud that looks like they're going into is actually on a smaller scale than the big explosion cloud.

I lent the anime to someone else so i can't check if this fits in with the anime as well. Can someone check whether in the anime you actually see them go into the cloud of smoke or if it's just their trails that go into the smoke.