He's good at what he does, he has never hurt anyone and does show a sign of confidence
What exactly does he do? Speak in an accent and pretend he lives in Call of Duty?
when you're around guns all your life you dont get so paranoid after a while
I'm not paranoid about guns. I have four of them sitting next to me at the moment, and keep them hanging about the house all of the time. I'm VERY comfortable with firearms of all kinds. However, there are certain safety precautions when dealing with them. We have four weapons safety rules for a reason.
- Treat every weapon as if it were loaded.
- Never point a weapon at anything you do not intend to shoot.
- Keep your finger straight and off the trigger until you are ready to fire.
- Keep your weapon on safe until you intend to fire.
How many of those does he violate needlessly?
If he was wouldn't he have killed someone or injured himself? Support your claim on how he is an idiot. 
Some people get lucky and have a very long streak of not hurting anyone with their stupidity. Doesn't mean they're not being stupid, or that someone won't get hurt eventually.