Players characters evading direct questions

[Kardwill]

it's not exclusively the gm's job. it's everyone's job, when there are reasons to suspect someone may have forgot something, to remind them.
because, fun fact, people who have forgotten an important piece of information generally don't know that they forgot it. when you forget a specific detail, you often also forget that the detail exhisted in the first place.
so, when somebody is apparently doing something stupid, remind them of the elephant in the room. that's everyone's responsibility. it's not a blame game

Oh, yeah, and the GM is completely allowed to forget stuff or get confused, too. Especially if it's stuff told by a player 3 games ago. That's the reason why I'm not fan of the old "the GM is always right" proverb : Quite often, actually, he's not ^^