Mal only talks well when he’s had the chance to go over the conversation in his head a few times, on his own, with the time to shade things in his favor a bit.  Maybe sleep on it.

When caught off guard, he doesn’t make such a good showing.

I figure a bunch of us are a little like that.  It’s just that we’re not trying to play fast ‘n loose with a corporate hot potato (i.e. other people’s day jobs)