I hate to use the word LUCKY, but being unconscious and still being beat on, is a terrible situation. Very glad he will recover completely.
Ambush is exactly right. Random violence with no precursor is another. Hard to defend against.
I had a friend who got caught in mistaken identity deal, guy thought he was someone else. He had just purchased an HK 91, and bought ammo for it at local discount store, he got in his van and decided he did not want to look stupid at the range, as he had never operated this type of rifle, so he loaded the magazine in the parking lot and placed it in the rifle. On the way to the range, a guy in pickup started harassing him at red lights, he paid him no mind and continued, then the guy went ahead of him and pushed him to the curb with his truck. My friend could not see the person anymore and thought he had passed out, No he was retrieving his pistol from under the seat, as he came out of the truck, my friend saw the pistol through the back window, never having shot the rifle, he jacked the lever and went out the side door on his van, and pumped 3 rounds .308 into the bed of the p/up, the pistolero changed his mind, entered his truck, jumped the curb, and went through a city park to escape. My buddy shaken, went 3 blocks to a Dairy Queen and called the police, they came out and studied the scene, picked up the brass and let him go, remarking on NICE rifle. Small towns are good that way.
Someone out to get you, unfortunately, probably will, unless arrested.