There's a look in John's eyes that says you're lucky Owen will be here any minute. He knows Sherlock is sore, but what better to get his mind off things than love?
When Owen does show up, there's a knock at the door before John goes to answer it and comes back with the doctor. He tells Sherlock he's doing well, and gets him ready for his dose of Methadone. Another month or so and Sherlock should be almost low enough to just quit completely.
When Owen is done, he lets them know that they can call him if anything is needed, and heads out. After he's gone, John is standing in the corner, smirking at Sherlock.