In a classroom scene (0:13:32 into the film), Margaret draws four X's around a circle: top, left, bottom, and right. When she draws the X on the right, she does not lift the marker and, having done it quickly, makes the X look more like a fish shape with two west-end tips of the X connected; however, the following camera angles show all four X's as full X's - no "fish."
As the movie begins, there's the sound of a car with a manual transmission shifting gears from 1 through 4. However, the car that's shown driving down the road is a Pontiac sedan that was never produced with a manual transmission. The automatic transmission in this car would never sound like a manual transmission. The sound department got this wrong.
When Tom is reviewing video recordings with a student, he tells the student to stop the video, and Tom himself impatiently hits a button on the keyboard to pause the video. However, when the film cuts to a shot of the screen the recorded video is still playing,
Tom is badly beaten in a bathroom, suffering injuries that would likely have landed him in a hospital as a patient. Instead, he makes his way to a hospital to disconnect Margaret's comatose son from life support. Tom's injuries would have been spotted by hospital staff and he would almost certainly have been encouraged to seek medical attention. Instead, Tom ends up in the son's hospital room, unimpeded by hospital staff, and simply turns a dial to stop the life support functions.
Two times in the movie a traditional camera that uses film is referred to as "analogical." Although analogical is a word, it's not correct in this usage. The word that should have been used is "analog" (or alternate spelling, "analogue")
When Margaret is lecturing her class, she refers to "100,000 million neurons in constant synaptic communication..." As an American, she would have said 100 billion, not one hundred thousand million as that is a British reference to numbers in the billions.