you must release the air as you surface from that deep, or you will force an embolism.
If you have to do an emergency ascent from a scuba dive you let all the air out as you near the surface.
That's only because you're breathing compressed air at depth. You don't have to release anything on a free dive like this because all the air in your lungs is still 1 ATM.
Pretty impressive video, I found it unusual you didn't see him equalize his ears much which he would have to do. Also notice no weight belt when he ascends, of course.
Also what would be so scary is at that depth you are no longer buoyant. Because of the pressure you're actually denser than water and would naturally sink instead of naturally rising/floating. So the deeper you go, the faster you would sink.
That he did it without fins is what's really freaky.
-edit-
bignateyk,
He had a weight belt on, you can see the weight at the small of his back.