After the Joes fall down the pit and hit the ground and Bazooka says "Ouch! That hurt!", his weapon is sitting up on the side of his right leg. In the next shot, the bazooka is behind him. Then in next shot, a POV shot of the Joes, Bazooka's weapon is laying on his lap.
In the shot of Alpine and Bazooka after the passage closes, Bazooka's weapon pack and his bazooka have vanished but the right strap is still shown.