I'm voting real. Stupid almost beyond comprehension, but real. They looked drunk and stupid enough to try it. Shooting him over the heart really takes the cake though, I was speechless when I saw that.
The wound and blood afterwards appeared to me to simply be the normal trauma you would expect to the tissue after taking a round on a vest. I'd venture the reason it was so isolated and punched an actual "wound" instead of bruising him, is he had the vest directly against his naked skin causing the force to be transmitted directly into him over a very small area, almost like being shot only without the penetration, oh wait that's what happened.
Over the heart at that, moron, jeeze, he's lucky to be alive.
Had he had a shirt or underlayer on under the vest it would have probably dissipated the force over a wider area and had the more typical bruising response.
Just mind boggling.
Also one or two of the guys did seen genuinely worried for a second or two, and it appeared and sounded like the one grabbed the vest and verified that the bullet was actually in the vest not the kid.
Amazingly stupid stunt though. The trauma from the impact could easily have killed him being located over his heart like that. Heck, if they didn't get him to the hospital after that he may have croaked, there are all sorts of things that could have gotten him from a clot to shock.