Your response contains a performative contradiction: you are asserting that humans are naturally logical while simultaneously committing several logical errors to defend that claim.
commenter’s specific claim—that adding a note about the definition of "if" would solve the problem—is a moving the goalposts fallacy and a tautology. The comment also suffers from hasty generalization (in their experience the test isn't hard) and special pleading (double standard for LLM and humans).
When someone tells you "you can have this if you pay me", they don't mean "you can also have it if you don't pay". They are implicitly but clearly indicating you gotta pay.
It's as simple as that. In common use, "if x then y" frequently implies "if not x then not y". Pretending that it's some sort of a cognitive defect to interpret it this way is silly.
> Decoding analyses of neural activity further reveal significant above chance decoding accuracy for negated adjectives within 600 ms from adjective onset, suggesting that negation does not invert the representation of adjectives (i.e., “not bad” represented as “good”)[...]
From: Negation mitigates rather than inverts the neural representations of adjectives