[mycroft]

There is a no-double-shot regulation pretty much world-wide in bridge that basically says that when the opponents do something wrong, you can't Hail Mary secure in the knowledge you'll get the ruling back the 90% of the time it doesn't work.

Other sports allow it: Gridiron Football is almost defined by it; Cricket minimizes the ways you can be out off a no-ball, so it's worth going after it (as long as you Know it's a no-ball). But it's not considered Bridge.

Different places in the world have different standards; some basically say "no doubleshot, but clearly inferior, but rational is okay", some are more restrictive. The ACBL is very restrictive, with a "continue to play bridge" policy; basically, you have to still look like an expert, if you are one, to get redress. It is explained in one of the Appeals books that this is because of the proliferation of pro-client partnerships, and (some) pros taking every inch of any advantage to get the good results that gets them the higher-paying (possibly even better) clients.