A very weird thing.
After stuffing a lot of itens in the safe, and removing them in a certain order, the safe can't hold anything else (apparently bearing an invisible load).

Steps to reproduce:
1.As the Corporate Liaison, retrieve the secret crate in your maint, go with it to the shooting range, shoot the crate open, pick up the sawed-off shotgun and shotshells box from it and also an extra shotshells box from the armoury.
2. Go to your room, open the safe and stuff in it on the exact order: Sawed-off shotgun. Two shogun shells box. VP70 combat pistol and the three VP70 magazines. (The third magazine won't fit in locker.)
3. Now retrieve from the locker the flask (or other non-weapon), and try stuffing in the third VP70's magazine. It won't fit. Remove more stuff. Eventually you will end up with a magical empty locker where nothing can fit in.
P.S.: Possibly, retrieving itens with your hand empty, or not empty (where the item goes to the ground) may make a difference. I didn't tested this bug throughly doing different things and didn't paid attention to this detail when I first stumbled on it. (Actually I was just prepping a "Pow-Wow safe", as is typical of this character when she ends up being a liaison.)