How do you confirm the election results itself though, when the election purveyors can't be trusted? Statistical polling has been a third-party check on elections for a century.
Well that seems pretty shaky. You're saying that in order to cast doubt on an election, I don't need to actually target the election itself? I can just generate a bunch of disinformation in an unregulated, less-scrutinized, adjacent channel?
To answer your question, you volunteer locally so that you're involved in the process, or you encourage somebody that you trust to do so, or somebody they trust, etc... You validate it by doing it validly.
Not with these margins
They don't really check anything, do they? When there is a discrepancy between official results and polling, the general response was that the polling missed something, not that the official results were wrong.