House's office is on the fourth floor of the hospital which, according to the directory by the elevator is the top floor. In addition, the elevator call buttons on the fourth floor only have a 'down' button available. However, multiple shots within the elevator show 7 floors.
Though this is probably intentional, to create a more visually striking scene, the show quite literally never correctly depicts the proper treatment for a flatline. Flatlines are treated with medication and cardiopulmonary resuscitation (CPR), not a defibrillator. Defibrillators are used to correct irregular heart rhythm (fibrillation) -- not the complete absence of one.
With, very, very few exceptions, characters in the series don't wear eye protection when performing surgery. It is standard practice throughout hospitals in the United States to do so. However, this was a deliberate decision made by the director for theatrical reasons.