Factual error: When the first train wheel hits the ground in the close up, you can see that it isn't made of steel as it deforms as if it were foam. And there is also no damage to the concrete road whatsoever, since the wheels are made of steel there should have been quite a big hole. (01:17:50)
Factual error: When Lincoln Six Echo escapes in Tom's car, he starts the engine using his fingerprint, which turns out to be identical to Tom's, since he's Tom's clone. Actually, fingerprints are formed in the womb and take shape mostly due to environmental conditions inside. They are not genetically defined or inherited, so Lincoln's prints should be completely different.
Chosen answer: It appears to be some sort of cable - it can be seen leading to the bracelet in the shot from above the bed immediately prior to the one where Lincoln unplugs it. Exactly what it does is never revealed, but it seems likely to be some sort of monitoring system, keeping an eye on Lincoln's health through sensors in the bracelet.
Tailkinker ★