No one ever said it is impossible. I never said anything like that. You made that up. I, along with everyone else, say that electrochemists take precautions to prevent recombination, and they always measures to be sure it is not happening. Usually with two or more methods.
In that case, surely when presenting a claim that anomalous excess heat is nuclear in origin, that measurement (on the specific experiment showing the excess heat) would then be a necessary (and easy to provide) addition to an experimental write-up?