The position of Gordon Dunn's corpse changes; from the first time one can see it, to when the police are on the scene. By example, watch his right arm closely.
The machine records a person's self-memory. At several times, when a record is played, the point of view is from the "recorded person". But near the end, as Sam is recording himself again, one should see the car from the inside (driver seat, as Sam was the driver), not an outside view as depicted.