This is one very, very lucky guy.
See here for MadOgre’s description. Scroll down to “BOOM HEADSHOT”:
Willie, the father of Tina, who made the sandbag rests fires a .50BMG, an Armalite AR-50 and it ricochets off of a steel plate that it should have easily penetrated. The bullet comes straight back and hits him in the head. You can see it hit the dirt about 15 feet in front on him before it clobbers him. Luckily he was uninjured. He’s a bit sore today, but otherwise fine. Lucky lucky bastard. He has been advised to buy lottery tickets while he still has so much luck. I don’t know about the timing, but you can hear the hit on the steel plate. Time that till the impact on Willie’s head… how fast is that 750 grain slug traveling? The range is 100 yards. Amazing.