Audio problem: At the party when Phil is playing the piano, there are several shots of the other band members. Multiple times they are seen playing their instruments, but they are never heard. The most obvious example is right before Phil finishes up his set. The saxophone guy is playing but you never hear it.
Continuity mistake: At the end of the movie when Rita reaches over Phil to turn off the alarm clock, we know the clock always goes off at 6:00AM. After turning off the alarm 2 1/2 minutes go by while they are talking and the clock should read 6:02, but when the camera pans to the clock it only reads 6:01.
Other mistake: When Phil is driving the car against the train he ultimately swerves out into a railroad crossing. However when the approaching train is shown from within the car in the last seconds before the two vehicles would collide, there is no crossing to be seen on the remaining track stage between them.
Continuity mistake: Towards the end of day 3 when Phil is drinking at the bowling ally, Gus says he pegs Phil as a glass half empty kind of guy. Phil is looking partly in his direction to his own left when he's saying this. When the camera cuts to a close up, Phil is looking straight ahead and then turns his head.
Continuity mistake: After Phil gets done with the weather report and then talking about his plans for the next day, he goes off to the side talking to some other men. He looks back and sees Rita playing with the blue screen. She looks over to her right at the TV which turns her head to the left of the camera. But then it suddenly cuts to what the TV is seeing and she's looking straight ahead, which means she'd be looking directly at the camera, and not the TV.
Continuity mistake: When the truck goes off the cliff in the quarry, we see it falling in a close shot, then it changes to a wider shot, except the driver's side mirror in the close shot is folded out, while in the wider shot it is folded in. The powder on the tires is also different. (01:03:20)
Continuity mistake: In the opening scene Phil is doing a weather report and is wearing a wireless mic on his vest. When they go off-air he jumps up and two seconds later the wireless mic is gone, neither on his vest or in his hands. Taking off both the mic and the transmitter would take longer than two seconds. (00:02:30)
Continuity mistake: Two chocolates are shown next to the alarm clock each time the clock is switched off or destroyed. They are in slightly different positions in every shot throughout the movie.
Continuity mistake: When Phil wakes up for the third time he immediately runs out of the hotel without speaking to anyone in order to get to Gobbler's Knob faster but when gets outside the piano teacher is already walking across the street. She shouldn't already be there if Phil went straight from his room to the street.