Engineers this is how the end users will use your product.
The French MAS-36 (in service 1936-67) feature a spike bayonet that could be stored inverted on the rifle. There was a small catch you could press on either side to release it from the gun to stow/affix it.
This is a very simple, cost effective, and sleak solution to the problem of what to do with a bayonet not in use. Unfortunately…
One day two intrepid French Soldiers with too much free time discovered this design issue when they stuck both of their guns together, and couldn’t separate them.
This resulted in a small hole being drilled on all rifles so an armorer could separate two stuck rifles with a punch, if anyone ever tried this again.
My bad graphic not clear? Check out Ian’s video on it: https://youtu.be/DA3VsMteAxk?si=Mg3lSEG54jGQTGZn [4:23]
No proofing could ever prevail against a determined idiot.