The proof is in the pudding. NOT! The correct expression is “the proof of the pudding is in the eating”. “The proof is in the pudding” doesn’t even make sense, not in today’s enlightened world. Pudding has no inherent, truth-revealing qualities, any more than tea leaves or the viscera of a newly slaughtered goat.
By eating the pudding, the qualities of the pudding are revealed to us. It’s science. Scientific method. Investigate, observe, experiment, conclude from evidence and facts. Looking to pudding for proof is superstition. Christopher Hitchens would agree with me.