When Lizzie, Miranda and Gordo sit down in class and begin to take their equipment out, Lizzie unzips her blue bag and takes a black case out of it - twice between shots.
When the guy is choking on a gumball in the cinema, in one shot he slaps his friends bucket of popcorn out of his hand to the floor. Then in the next shot the popcorn bucket has reappeared in the friends hand.
When Jo and Sam McGuire are talking about Lizzie, after Jo received the phonecall from the cinema, in frontal shots of Sam he holds a spanner down on the table, but in shots from behind you can barely see that he is actually holding the spanner by his face; this repeats a few times. Also during the conversation Sam leans his head to the right as he says Lizzie is a "lying hero", yet in the next shot his head is suddenly upright.
When Lizzie runs over to help the choking man by giving him the Heimlich maneuver, in wideshots the bag she had on her left shoulder has disappeared. But in closeups the bag is on her shoulder again.
As the guy is choking on a gumball in the cinema, Lizzie runs over to help him (by giving him the Heimlich maneuver.) The guy has three red sweet (candy) laces hanging around his shoulder; and the amount keeps changing from shot to shot. In one shot one falls off, then it is back on, then two fall off - but in the final shot of the gumball being spit out of his mouth, all three laces are around his neck again.
When Lizzie and her friends plan to see a rated R movie, Gordo says the reason is "adult situations, mild violence and brief nudity." In real life, the Motion PIcture Association of America (MPAA) gives "mild violence" as a reason for PG-rated movies. For R-rated movies, the reason would either be "brief violence" or just "violence."