I don't know if anyone else found this yet but a few days ago I found this glitch on my casual run through. The way I understand it is when an enemy is staggered really close to or against a wall and you can perform a glory kill that moves your character to a specific location it allows you to clip into a wall. Proof: You are allowed to move after the clip I just didn't think to do it until after I uploaded the video. The footage is taken off of my ps4. I hope this helps for any runs and I'm currently experimenting to see if I can come up with anything else. If I find out anything else I'll add it to this thread.