[Flatly:] Maybe later.

[He doesn't catch the bag, just tilts his head out of the way so it doesn't hit. He'll put it away later.]

The other apology for something I did afterwards. After Law dropped you off the other night, I looked at your journal. [...] You'd left it out.

[He doesn't say that as an excuse - it was out, but it wasn't open.

And this isn't a minor thing like ditching him was. Shikamaru watches him carefully now, anticipating a different reaction to that.]