This is why I’m paranoid about selecting the channel my microphone will go out on, and whether or not my interphone is engaged. You can get a “stuck mike”, where the button that allows your microphone to go out on whatever channel you’ve selected doesn’t release & keeps sending your microphone out after you let go of the button / trigger. Just a whole lot of opportunity for embarrassment. I never make a PA using my headset. There is a microphone on the center console that only goes to the cabin PA system, so it the only thing I ever use to make PAs. Not that I talk that way about FAs or anything, but this kind of thing happens with some frequency & I’d like to be sure it doesn’t happen to me.