Originally Posted by JAS84:
“He didn't rob him, he traded 11's fobwatch for that coat (which Clara was annoyed about when he told her, lol!).”
It was the wrist watch he was wearing that he swapped.
The Doctor was wearing it when he left Paternoster Row but didn't have it when he later met up with Clara.
He does have a wristwatch again by Into the Dalek (so either just got a new one or the continuity people messed up).