Revealing mistake: Matt, the boy killed at the beginning, has very short hair. His dummy (the one hit by the white van) has much longer hair. (00:05:40)
Revealing mistake: The camera occasionally pans sideways through walls as characters travel from room to room. In two instances, a visible edit can be seen between the rooms, revealing that they are not in fact adjacent parts of the set, but rather were spliced together. In the latter of these two, an electrical outlet disappears mid-transition.
Revealing mistake: When Miles is driving and doing a crossword puzzle the car's odometer is at 0.
Suggested correction: Already posted and corrected. The odometer isn't working. It's broken. It happens.
Revealing mistake: Tim parts his hair on the left side, but during dinner it was parted on the right side. After dinner, when Tim was coming down the steps with his sister, his part was on the left side as usual. It was the same evening because he was going to the party. (00:18:15 - 00:20:09)
Revealing mistake: When John uses Scorpius as a shield and takes cover in front of him, as John fires at the Tregans behind Scorpius, there are round black devices attached to the back of Scorpius' suit that are there for the gunfire special effects, which suddenly appear then disappear after.