The problem isn’t pissing on (actual) active shooter situations then, it’s having these situations for no reason. If they’re drills, then you should be able to excuse yourself to go to the bathroom. I can’t think of any other reason a school would specifically go to “active shooter situation” for hours without an actual shooter.

Whatever it is, if it’s a real risk then it’s still better to wet yourself than risk your life to go to the litter box. If it’s not then the protocol needs working on: why is it taking so long? why can’t you go to the bathroom when there’s no danger?