I found another story where the guy tells his story. In short, gun sale between the two, gun gets dropped and it goes off as he tries to catch it. After that he blacks out and has no memory. Apparently during that blackout he leaves, returns, shoots the guy four more times in the head.
That’s a pretty big sea story to sell. He pled guilty to murder II rather than go to trail for murder I.
It doesn’t say what kind of discharge he got, but apparently it didn’t keep him from working for the water district.
The owner over-oiled the gun. He drops it and shoots the guy in the head. Later, he comes back to pick it up, and he juggles the slippery gun as it fires repeatedly. Could happen to anybody.