Factual error: During the defibrillation scenes, the 'doctors' rub the paddles together before delivering the electrical shock. Yet there is no gel on the paddles, and no gel pads on the 'patient' either.

Factual error: Asystole (the lack of cardiac activity, also known as the 'flatline') is not treated with defibrillation (electric shocks) but with alternating doses of the drugs epinephrine and atropine.

Continuity: Julia Roberts' character's father kills himself after returning home from the Vietnam war (presumably in the early 70's) addicted to morphine. The problem with this is that he kills himself in a 1978 or 79 ford pickup - Ford did not produce any pick-ups with square headlights until those years.

Continuity: In one of the final scenes where Kiefer Sutherland puts himself under, before he injects himself, he doesn't put the suction pads all over his face and chest to track his vitals. Yet when his friends come in, the first thing they check is the EKG machine to check his vitals, which it is displaying. After this, they show Sutherland again, and he has the suction pads on his body. How did they get there?

Revealing: When Kiefer Sutherland first undergoes the experiment, the doctors use a small mask to put him to sleep. When he is supposedly waking up, Julia Roberts asks Oliver Platt to help her with oxygen.  He hands her the same small mask they used the first time ie. anaesthetic. Just for a second she has a look on her face which says "this is the wrong mask" and she tries to hide it with her hand. For the whole rest of the film, the other doctors use a bigger mask when giving oxygen.

Continuity: When Julia Roberts' father supposedly kills himself in the truck there is a golf ball size hole in the windshield. If he'd used a gun with large caliber the windshield would be destroyed and there would be hair, skull and brain on the windshield, not just blood.

Continuity: When we first see Kevin Bacon, he has an argument with Kiefer Sutherland as he packs his stuff into his truck. At the end of the argument, Kevin pulls the rope down, pulling the canvas tight and closing the back of the truck. There is a shot of Kiefer, then back to Kevin who pulls on the rope and closes the back of the truck again.

Factual error: When they jump-start Julia's heart, she's wearing a bra. As medical students, one of the first things they would have learned is CPR and the use of defibrillators. They should have known to remove things like that or the electricity would have left burns on her chest, particularly where any metal touches.

Factual error: Kiefer Sutherland crosses a vacant street and enters a subway station where he encounters the child ghost that is haunting him. The corner exists, it is called "Six Corners" because three streets come together, and is in Chicago's Wicker Park Neighborhood. However, the train station at that corner is an elevated train, not a subway - this scene is filmed at Damen, Milwaukee, and North Avenues. The real Six Corners is Cicero Ave, Irving Park Rd, and Milwaukee Ave.