system
A chat on subreddit /r/NoStupidQuestions
human
There’s a badge cam video on YouTube of a man sitting down, handcuffed behind his back, in a police station, and VERY drunk who manages to grab a cop’s pistol out of his holster and almost get a shot off. Not to mention, there are plenty of people who are weirdly flexible and can get their cuffs from behind their back and up front. 

Reality isn’t that simple. Even when someone’s restrained doesn’t mean they’re not a threat.
gpt
Yes, and in your example it was the cop's pistol. I believe the person I replied to was talking about a hidden weapon on the non-sworn civilian's body, when said person is being approached by a cop.

Reality isn't simple, but adequate training should provide you with reasonable options on how to deal with some standard situations.