Corrected entry: As Cuddy is making the deal with House, how much time off from Clinic duty for a week off his vicodin, while the camera is behind Cuddy you can see there is bright sunshine on House's head. The shot switches to a camera behind House and now his head is shaded.
Corrected entry: A kid is being taken to surgery to remove a magnet he swallowed because it may be stuck in his upper intestine. House diagnoses that the magnet is already in the lower intestine by taking a scalpel and showing that it's magnetically attracted to the lower abdomen. Surgical scalpels are made of high grade stainless steel and are not attracted by magnets.
Correction: Some scalpel blades are made of high carbon steel or tempered steel. The material used depends on the alloy content of the stainless steel. Certain types of stainless steel may be magnetic even if they do not contain nickel.
You Don't Want to Know - S4-E8
Factual error: Amber triggers a fire alarm by heating the sprinkler with her lighter. Unfortunately that fire sprinkler doesn't detect heat (or smoke). The sensor is located between the ceiling lamps, about two meters from the fire sprinkler. (00:09:00)
Suggested correction: Heat applied to the sprinkler would cause it to activate and spray water. All modern fire systems will detect this water pressure drop and activate the alarm.
Factual error: In episode 414, "Living the Dream," the patient Evan is given a nerve function test. We see Kutner and Taub performing the test by puncturing Evan's legs with needles. Modern nerve function tests actually rely on electrical impulses from a small computerized device, with no needles necessary.
Suggested correction: House ordered an EMG (electromyography) to test for motor nerve entrapment. During an EMG, one or more small needles (electrodes) are inserted through the skin into the muscle. The electrical activity picked up by the electrodes is then displayed on an oscilloscope. An audio amplifier is used so the activity can be heard. When an electrode is inserted, a brief period of activity can be seen on the oscilloscope, but after that, no signal should be present.
Correction: The light is still visible in the shots from behind House, just not as easy to see.