Continuity mistake: After Mr. Butler uses tongs to put salad on his plate, he takes a second scoop - but the first scoop has disappeared and his roll has moved (about 90°) on his plate. (00:06:10)
Continuity mistake: When Lucas and Mr. Butler are playing chess, the timer clocks do not consistently move forward. The timer clock on the left goes from approximately 10.6 to 10.8 to 10.4 to 10.9 and back to 10.4. The timer clock on the right also goes backwards from about 10.95 to 10.8 and then stays at 11 for three moves. (00:12:10 - 00:12:35)
Continuity mistake: The final classroom scene contains some continuity errors. The podium is closer to the board/wall a couple times and is later at an angle instead of being parallel to the wall. The words Lucas wrote on the board - "I have not deserved this" - is in bolder/darker writing during the fight and the word "deserved" is not underlined after Lucas underlined it. There is also no explanation or even hint as to how the detective knew to go to Mr. Butler's class (or the school in general) that night. (00:12:25 - 01:19:18)
Continuity mistake: Mr. Butler parks his car close and parallel to his house. The night/morning Lucas slashed his tire, the car was parked away from and perpendicular to the house. It is worth mentioning that instead of Lucas going on the passenger side of the car where he would be hidden between the car and the hedges, he slashed the tire out in the open where he would have been more likely to be seen and caught. (00:27:15 - 00:28:30)
Continuity mistake: Mr. Butler returned the paper Lucas wrote ("A Defense of Iago"), but it is back in his home office when he uses it to highlight words in it that were also in the paper he believed Lucas substituted in his application to fill a professorship position. (00:35:37)
Suggested correction: After watching the movie on a larger screen, it appears Lucas may have left his "B+" report on his desk in the classroom - a black cover page can be seen vertical to his desk and behind the seat in front. This means that Mr. Butler had the opportunity to take the report home again. [00:26:33].
Continuity mistake: Lucas received his mid-term grades in the mail BEFORE Mr. Butler actually entered his grade on the computer. Lucas got the mail and took his unopened grade report to his bedroom then the camera shifts to Mr. Butler contemplating what grade to fill in for Lucas. Mr. Butler made the entry (grade not shown) and closed his laptop. The camera returns to Lucas, who opens his mid-term grade report and sees the "F" from Mr. Butler. (00:51:21)
