Like in title, I was in elektro once on top of the powerplant building there, and i saw two people hitting a dude that was unconscious inside firestation left door opening, the big red doors. And the bullets, x2 7.62 rounds with a mosin just ricochets off the middle as if the doors were closed, but they were open...

Also another bug i've seen is that when someone is inside a pine-tree they get immune to bullets. maybe you should look into that :)