You know, I probably should've made that connection, but didn't. lol. Considering Sara's "meh" expression when Warrick said he hoped she had better taste now, and the fact that Grissom was hunting her down like a predator not two episodes earlier, I'd say that it was probably Grissom's idea, or at least at Grissom's insistence that she think of something that would make her feel like he trusted her. The whole point of her being mopey over his break, I thought, was that she didn't really feel included in his life or his decisions. Yeah, but even you point out that it's not just a role reversal, it's an intention reversal.