Visible crew/equipment: When Sean Bean puts the microbes into Ewan McGregor's eyes, the crew is reflected in his glasses. (00:15:05)
Visible crew/equipment: When the first train wheel falls down you can see a cord attached to it, in the next shot the cord is gone. (01:17:50)
Visible crew/equipment: When Tom Lincoln runs up the stairs to get his shoes and opens the door to his room, you can see a cameraman reflected in the glass. (01:34:40)
Visible crew/equipment: At the end of the freeway chase, when Laurent steps out of the passenger side of his car, a camera and several crew members are reflected in the door of an approaching vehicle.
Visible crew/equipment: During the freeway chase, when both the Hummer and the Dodge Magnum are shown flipping over at the same time, the "Bay Buster" camera truck is briefly visible in the background.
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 ★