At the beginning of the film, when they are calibrating the system, Lillian asks Michael what he sees, and he replies, "Clockwise rotation." However, the two superimposed images of the test pattern are rotating counter-clockwise.
When Lillian is recording her death, the tape reel is almost empty and it only records for about 30 seconds. After the funeral, when Brace and Hal are in the lab , the reel on the table is full. Then later, when we see the tape reel in the tape lab, it's almost empty again.
When Michael gets home from work at the beginning, he walks into his bedroom and turns on the light. Before the light comes on, the wall where the switch is, is illuminated by outside light. This light disappears an instant before the room light comes on.
Twice, when the robot arm sets the "death tape" into the playback machine in the secure lab, you can see cellophane preloading the tape into the player, to give the effect that the tape is self-loading.