Ten doesn't want to look back up once he finds out that he's not alone because how awful his face most look from crying.

He only whispers, "Yeah..." And is trying to see that at least Rose isn't with the Daleks and Cyberman in the void. She's with her family now. So close and yet so far out of reach. And he kept his promise. To return her safe to her mum.

"Problem is. Thar shouldn't be any reason that this should be hurting. She's safe - in another universe but safe..."

Lying to himself again, tsk, tsk, tsk.