Continuity mistake: Dr. House is listening to a patient's heart with a stethoscope. However as the shot cuts to his face you can see the stethoscope is not in his ears.
Audio problem: Just after House has diagnosed the nun, one of them comes out to thank him. She says, "When I break my leg..." but her lips don't move.
Answer: You have the right episode. The big deal at the end about the letters on the pills was to show that Brandon had the wrong pills all along. House was smiling because he was right.
MoonFaery ★