Leia’s “Oh, what, me? I don’t know what at all you’re talking about! I’m totally innocent here!” act is, in fact, spectacular here. And works in context.

They both know exactly what she’s done. But Vader simply can’t prove it on a technical level. And how pissed he is.   

It’s not a plot hole. It was some epic trolling from Leia to this absolute mad man she detests.