Well we all know the bugs. Sure enough sometimes zombies glitch through the floor or ground and hit you, sure enough it's annoying, just as annoying as the ladder bug that you die from, or going through a floor at a fire station tower, or spawning under a rock and see your 12k hp character die helplessly. Should we then allow morals dictate when and when not to exploit ? Certainly not. In rare cases, yes you will die and you should deal with it. In most cases, GTFO where the zombies glitch when you notice you're being hit and you'll be fine. If you can't GTFO, you were most likely going to die. Right now you can just use that exploit to avoid death in any circumstance, pure and simple. In a game where death is inevitably where your character is going towards, it is of utmost importance.