I understand that line of thinking, but unless I missed some dialogue, I think Aymeric honestly forgot about the Eyes of Nidhogg. It'd have been much more consistent and forgiveable if at least after the fact and after Estinien is saved, he says something along the lines of "We really shouldn't have thrown the Eyes of Nidhogg away so that anyone can find them", or at least acknowledges that it was a decision that will very definitely come back to bite Eorzea in the ass.
