Attempted realism, be it in fiction or gaming, is a means to an end, not an end in and of itself. So the question becomes, "what are you (collectively) trying to achieve?". In most genre fiction I'm familiar with, and thus in most role-playing game campaigns, the answer is "a world of high/cheap/improbably melodramatic adventure".
So I try not to let a surfeit of realism interfere with that.
A prison in a game is not a meant to hold a PC for any length of time; it's meant to be escaped from. Likewise, the hangman's rope isn't meant to break a PC's neck, it's there solely to afford the other PC's the chance to shoot it in two.
edit: which isn't to say PC's can't fail in a given escape plan, or fail to free a comrade about to be hanged, just that these bad ends should never be a fait accompli. They should be game-able situations, or else they shouldn't be part of the game.
Also, if I wanted some kind of forum with which to work out my personal ideas concerning the relative plausibility of various scenarios, the last one I'd choose is a role-playing game.