Sorry for not directly echoing 'it should be banned fast', but since I've teambanned people for this I'll need to further explain why it is already unfair in way too many ways to allow. I don't even think we need to add it to the rules since it should be common sense.
First off, let's assume all attacks are instakilling crits. That's basically how it is already - either that or the blues won't be able to stop them in time for more swings.
This means that in order for a prisoner to be kos, a random innocent prisoner's day has to get messed up, throughout no fault of their own. It's the same as that idiotic order where "if one person in a cell rebels, everyone in that cell is kos". Ever heard that order? If not it's because those who used it have been banned or explained not to, as common sense should dictate that prisoners shouldn't be murdered purely for spawning in the cell with an afk person or someone who chooses to rebel.
I really don't want to go too deep into something as unbelievably uninteresting and boring as the very jailbreak ideology itself, but in the ideal round of jailbreak, the winning red should be the one who is the best/fastest at a minigame (luck-based minigames are the exception), has the quickest reaction time, and is able to follow every order perfectly, and dodge the tricky ones. Not the one who happened to not spawn with an afk person in their cell or not stand next to a madman during 'trust day'.