Question on MSNBC right now..

[Whiskeytide]

10. I think it is a simple as ...

... he believed Mueller didn't know as much as Mueller knows, and thought he could get away with lying. It's a good bet his "lies" were more akin to not telling everything rather than an outright, black & white untruth (I'm just assuming he'd try to make it as gray as he could since, though corrupt as hell, he doesn't seem to actually be that stupid).

He could be hoping for a pardon (trump's increasingly hostile anti-Mueller tweets suggest that trump has some kind of a plan that is not in any way dependent upon Mueller's good will, and a stack of pardons could be a part of that - he's certainly ramping up his efforts to legitimatize Mueller). But I suspect trump believes he can only get away with so many pardons before he really starts to lose favor with congressional republicans and possibly even less strident members of his base. He's saving the pardons for people closer to him.

Manafort could actually be doing it in cooperation with Mueller as a way of keeping his family and himself safer from possible retribution. (Real tin-foil hat stuff there, but I suppose it's possible).

But I really think he just didn't realize what Mueller had. When you live life lying and scheming about everything, you tend to forget when and where you dropped breadcrumbs. Getting your lies crossed up is the logical result.