So I tested the spot out. I died every round with only myself, with 1 other guy, with 3 guys, and with 4 guys. A bhopper was able to get into there easily every time. Times by my self 2-3 zombies would push in and kill me. I'm impartial to how illegal this spot really is because its just the small lip of a crouch to get in, and we got killed easily every time.