In the video when eminem is up in the building and is going to jump from there, notice he has a visor in his head, and when he jumps and is in the air, it disappears, but almost at the end when he is see through a window in the air, it appears again, then it disappears.
miranda is absolutely correct! you could have your hat fall off when you jump but the thing is that it CAN'T be back on your head when you're near the bottom!
Ok, heres what I think....the hat falls off when hes falling and when he hits the ground (if that even happens, i cant remember) he finds his hat and puts it back on! Or, if he never hits the ground then maybe he caught the hat flying in the air? you never know.