When Karen is hanged, it appears she has been executed by the "long drop" method in which the victim is allowed to fall several feet in order to break her neck. This is apparent in the way Karen's body disappears entirely from the frame when the trap door is sprung. Having matron Walker weigh Karen beforehand is consistent with the procedure for long drop hangings so that the executioner can calculate the slack needed to ensure a quick death without decapitating the victim. However, the rope we see attached to the gallows is far too short for a long drop hanging. It has hardly any slack at all and would have resulted in a "short drop hanging" in which the victim would have fallen less than a foot and remained completely in view at almost the same level as her executioners while she slowly strangled. The absence of slack in the rope had already been confirmed when Mrs. Wakehurst inspected the gallows the day before and tugged on the rope. If there had been more rope above the frame than we could see on screen, Wakehurst would have released it when she pulled. The rope was clearly only as long as it appeared to be with the knot at about the level of Wakehurst's chin. In short, it is physically impossible for the gallows rig shown to produce the effect displayed in the film where the rope grew several feet in between edits.
When lightning flashes as Jack helps Ann-Marie to the passenger door of his truck, Jack briefly disappears and Ann-Marie is again shown outside the driver's door.
The camera is visible in the car side screen when Mark and Ann-Marie first drive up to the prison.