201 votesChaoscreature7 commented
This isn't a bug it's a normal part of many gun games. Not all walls can be shot through either as it actually determines on the type of wall you shoot through. Just like in real life bullets can go through different types of walls like wood for instance. Have you shot someone hiding behind a couch. It's quite possible since the couch is determined as an item bullets can pierce. On the other hand the only real bug I've ever seen in the MP is people using a glitch with their shivs to kill someone through the wall.