Corrected entry: During the scene where Dr. Challis is in the bar, he asks the bartender to change the tv channel after getting ticked off at the continuous Halloween song commercial. The new channel has a football game playing on it. According to the timeline for the movie, this day was Friday, October 29th. Very unlikely any televised football would be playing on television on a Friday in October, even college football.
Corrected entry: When Buddy Kupfer Sr. is bitten by the rattlesnake, we see the snake bit him in the lower leg and then continue to yank and tug and hang onto his leg for upwards of four seconds or more. In reality, a rattlesnake bite from start to finish is under a second, and they cannot/do not hang on and/or yank during the bite.