According to Deputy Sheriff Kevin Potter two men were out hunting.
One of the hunters was inside the boat with the dog, and the other hunter was in the water setting up decoys. The guy in the water had put his 12-gauge shotgun across the bow of their boat.
The dog got excited, was jumping around inside the boat and then it jumped on the gun. It went off, shooting the [decoy setter] in the buttocks.
(The dog) did something to make the gun discharge. I don't know if the safety device was on. It's not impossible the dog could have taken it off safety. Source
The man is recovering while he reviews gun safety rules. The dog will not be charged.