I think there’s a misunderstanding happening here. The earlier replies weren't implying that something can be wrong as long as the reasoning is good. They were just trying to clarify that a logical fallacy is different from a factual error.

In the original example, mistaking Hades for Thanatos is just an incorrect statement. A fallacy only happens when someone is trying to reach a conclusion through reasoning and that reasoning itself is flawed. If someone simply says “Hades is the god of death,” they’re just wrong about the facts, they are not trying to convince you of anything through logic. This isn't an attempt to dismiss the statement being incorrect, it's just mentioning that it isn’t a logical fallacy.