Execution Botch Device

Some countries/jurisdictions will not execute a prisoner twice (as in, after a badly botched attempt.) Consider a covert implant that prevents a given type of execution method from working properly, at least for a while. For example, an electric chair might be shorted out by implanting under your skin a network of highly shielded (electrically and thermally except at the ends) cables that would rout the current around sensitive body parts and short the chair. Or suppose a device that detects a Lethal Injection and releases antidote. Or, an artificial bone in the neck that prevents hanging (fanciful, true.) Anyways, you can't defend against every single method, but ideally the government that sentences you to death would let you choose the method and would not execute you twice, as is the case in some places.