"Oh, it was the other Rose... though I'm sure Rose Tyler would be interested in joining either way, seeing as the Doctor is already in."
Can you hear that slightly higher pitch in his voice? That's the fanboy in him, yawning and stretching his legs. Talking to Rose Tyler is definitely on the top ten of coolest things to do in underwater prison and he should definitely do it more, but that's not the point of this exercise.
"I'll pass that on. I'm not sure if she's qualified but she helped me a lot yesterday. Seems to have the right idea about things at least... Sam probably agrees."