Yipes!
Learn, hopefully, and live... Glad he didn't shoot a camera person.
This unfortunate accident due to firearm mishandling could form a decent discussion on how to carry a capped gun or whether to cap or prime a muzzle loader gun you are carrying through the mountain brush capped until you are ready to take the shot. So here goes from my perspective, knowledge and training so far....
The 3 main NRA Gun Safety Rules are as follows:
1. Always keep your gun pointed in a safe direction.
2. Always keep your finger off the trigger until ready to shoot.
3. Always keep your gun unloaded (round unchambered I read it as) until ready to use.
These rules are important but it seems to me that in an instance when for what ever reason the situation becomes unmanageable, having an unloaded gun or a gun where the round is unchambered, would help alleviate an accident entirely.
Grouse hunting, pheasant hunting, jump shooting deer etc.and whatever seem to demand a hunter have a shell in the chamber. Hammer guns with a shell in the chamber or a cap on the nipple or a primed pan are ready to shoot. Slipped safeties may also cause problems SO back to rule 3.
As a professional big game hunting guide for 18 years our camp rule was never chamber a round until ready to shoot. Double guns were carried w/no shell in the chamber or the action broke open. Some guide hunters keep their bolt in the up position meaning the action is not fully closed and the gun can't fire even with a shell in the chamber. There are all kinds of variations to this given the guns action type.
In my opinion the parts of a second it takes to chamber a round (in a bolt, lever or pump gun) is worth it in terms of safety even compared to maybe not being able to take the shot. Safety trumps the inability to make the shot in every situation.
There are all sorts of situations in the field where I may chamber a round or cap my gun and when those situations change, I will uncap or unchamber the round in my gun. A capped or primed gun is ready to shoot. Safeties, hammer covers, tethers etc. do not negate the fact that the round is chambered or in the case of the muzzleloader that the nipple or pan are primed.