The headshot bug is seriously annoying, yes.
Coupled with the psycho physics and weird AI there were some interesting shoot-outs I had: about 150m away from a gunners' nest, I shoot a guy in the head, blood gushes out of it into the air, the guy stands up and stutters in his place, mounts the gun again, doesn't shoot back, and I repeat the process 10-15 times before he actually dies.
Blood coming from his head, 15 times.
I'm no surgeon, doctor or field-medic, but I'm fairly sure that a korean with a freshly fired bullet lodged in his skull isn't a happy dandy korean, even less so when there are about a dozen of them stuck in his cranium.
Meh.