When Data is depolarising the power grid while holding the cab back with his left arm, the scene cuts to a view from over his right shoulder. There is a brief moment when his right arm is moved back to show his left hand. Since his left arm is no longer holding the cab, it should be in motion running him over. Even so, the wheels are still heard burning on the road as if still being held back.
When the train passengers are having the party at the end of the show, Worf, Troi and Data are in attendance and each has a glass of champagne. When the rest of the holodeck characters disappear, they are still holding their glasses. When the holodeck scene disappears, the glasses of champagne that they are holding should have also disappeared.
Data is shown working in the uncovered manhole to bring down the power grid, after which Geordi tells him to stop what he is doing. The very same footage is reused when Data brings the power grid back online.