My point is that this thinking is a fallacy precisely because it is orthogonal to the argument being made. It is neither evidence for nor against the argument.

My point is that this thinking is a fallacy precisely because it is orthogonal to the argument being made. It is neither evidence for nor against the argument. You are making some sort of argument for heuristics, but heuristics are called such precisely because they are not solutions. The correct answer is to independently validate the claims, or evaluate the merits of an argument on their own ground. That's tedious and often not worth the effort, and that's OK. We use heuristics all the time -- you don't ask your friend for his proof, because you use the heuristic of trust instead. But at least acknowledge that it's a heuristic and stop trying to claim it as a solution.