>Maybe we are both right, as long as he's not denying that A is itself.
You can both be wrong, you cannot both be right.
>Maybe nobody is a normal perceiver. With regard to logic alone, it doesn't matter.
That's ridiculous. If I perceive the law of non-contradiction to be that A can be non-A, then surely it matters.
>I don't need to be able to perceive the whole universe to know that things that are not themselves don't exist, never have and never will.
How do you know? You certainly do not have universal knowledge.