All my sympathy goes to the guy who got shot, none left over to the shooter, who may get a felony conviction and hard time for an 'accident'. It was an accident only to the extent that I'm willing to believe that he didn't want the gun to go off... but that's not the whole story.
Every firearms safety class I've ever taken pounds away at Rule Number 1: assume every gun is loaded. Rule Number 2 says, don't point your weapon at anyone unless you intend to shoot.
I've been chewed out by the Range Safety Officer for negligently allowing my pistol to point anywhere but down range, even when we both know the magazine is out and the barrel has a safety flag going down the muzzle and out the breach.
To handle a firearm in a car with other occupants is just asking for trouble. It may not come often, but when it does the consequences are unthinkable.
So yes, this was felonious negligence, not an 'act of god' type accident.