Facial deformity is on the left side of the face, covering the left eye, while the right eye is fine. On the last shot of the episode, they show a shot of the boy after surgery. Then the right eye is damaged and left is fine, while it should have been the other way.
House initially rules out the correct diagnosis of Lyme Disease because they cannot find the trademark rash from the tick bit. While the rash is a good way of confirming the diagnosis, one in 5 patients present without one, making its absence no good reason to rule out the condition.
A patient with a pacing wire has his pacemaker turned off while Dr Kutner stands by holding up defibrillator paddles. Turning off a pacemaker will make the heart slow down and stop, not fibrillate. Even if fibrillation was a danger, paddles would not be used - external defibrillation pads would be placed on the patient's chest and back well in advance to avoid wasting time.