Bullshit. You test and inspect everything that goes into a actor’s hands doesn’t matter what it is particularly when it comes to fx and stunts. Throwing shade on a prop house is a skeezeball move. Our industry has best practice checks that you do at multiple points - upon purchase before the day, when you load up and immediately before you hand over the weapon. Even if they somehow bought their live rounds from a prop house you would have to ignore at least three levels of check you should be doing to get that far, nevermind the weapon was left on a cart and handed over by someone unauthorized.
It doesn’t matter if it’s a breakaway ceramic piece or a round - you buy extra then what you need for camera and you check…