Looks like another execution to me.

[OK Corgi Rancher]

Not everyone drops their gun just because they fall. You can clearly hear the kid say "I don't have it" or something like that in response to the deputy. The deputy stops saying that afterwards. They deputy thought he was still holding the gun or possibly couldn't see the kid's hands. Of all the things about the deputy's actions to criticize, that would be way down on my list.