The first bomb explodes on the ground before the bomber starts to drop its load, and since the plane flies from right to left, the bombs explode in reverse order, with the last-dropped bomb detonating before the first one, rather than the other way around.
As aggressively determined as Daffy Duck had been behaving with his shotgun, the bear should not have been able to just casually waltz back to where Daffy was standing after blasting off a patch of the bear's fur; Daffy would not likely have been just quietly standing there all "meek 'n' motionless" as the bear approached him --- he would have continued shooting at the bear. It's not even as if Daffy's gun was out of ammo and so he couldn't have gotten off any more shots at that time --- the bear flicks open the gun's breech and dumps out a whole big handful (or should I say, "pawful") of shells, so obviously Daffy's gun was a specially-designed weapon that had a humongous super-high-capacity magazine that could hold maybe 25 or 30 rounds.