Absolutely perfect missing scene, and exactly how I imagine Donna getting him to tell her where Rose is. Whether it would have happened now, just after River (urgh, but the Doctor was upset, so...) or some other time, I don't know, but it would have happened just like this :)

Tiny, tiny Britpick, but any time i see it done it jolts me:
“You could leave, is all. Your choice.

We don't say 'is all'. If we say anything along those lines, it would be 'that's all' - but in this context we might not use anything. Maybe we'd say it as "It's just... you could leave. Course you could. Your choice."