When the main character checks the security footage, the dates don't line up with the current date.
When the main character is brushing his teeth, the time stamp wasn't removed from the shot.
When the main character is washing off his bite mark, the time stamp on the security camera is missing.
On the final day, the grandpa said that his car is totaled, but the car is visible later in the day, and it doesn't have a scratch on it.
Right before the dad leaves, the dog's hair grows in-between shots.