Continuity mistake: When Austin is typing to Sam from his bedroom, the very first book on the shelf in the background keeps changing, over and over again. This occurs near the start, when they are still unknown to each other, and also when he tries to write to her after the pep rally incident.
Continuity mistake: When Austin is putting up the "Have you seen Cinderella?" fliers, in one shot he puts up the second flier on the blue door on the lower left side of another flier, but in the following shots, the flier is near the center, then to the right, and then back near the center again.
Continuity mistake: When Sam and Carter leave the dance and run to the Mercedes so Sam can get back to the diner by midnight, in the long shot before they reach the car we see, one, that Sam pulls off her mask as she's running, and two, there's a rearview mirror on the Mercedes. In the following shots the mask is still on her face, and the rearview mirror has vanished again.
Continuity mistake: When Sam is at Carter's house to give him a lift to school, Carter (in his Snoop Dizzle look) is holding the script in his left hand and the bag's strap falls off his right shoulder when he sits down. Next shot, the script is in his right hand and the strap is back up on his shoulder.
Visible crew/equipment: Just before Sam and Carter show up at the pool for Carter's Zorro reveal, when Shelby, Caitlin and Madison are walking towards the camera as Caitlin says, "He was so mysterious, but really obvious...," the shadow of the crew's equipment moves forward with the trio, on the ground behind Caitlin. (Visible on fullscreen DVD.)
Continuity mistake: After Sam loses the two parking spaces to Shelby and then Austin, when it cuts to Shelby, Caitlin and Madison walking down the corridor pushing everyone aside, Madison is holding her textbooks with the books' spines facing forward, then facing the opposite way, and finally back again.
Continuity mistake: When Sam and Carter arrive at the pool, before Carter reveals himself to Shelby, the poolside gate and banner cast a shadow on the ground, to the right. After Carter is belittled and splashed, when he joins Sam the shadows cast are now longer and farther back. (Visible on fullscreen DVD.)
Continuity mistake: At school, when Austin is putting up the Cinderella fliers, he tapes the fourth flier on the bulletin board under the word "pep" and over the letters "Fri" in the word Friday. Next shot, the flier has moved to the left, and is taped beside both words "pep" and "Friday".
Continuity mistake: After young Sam has carried the box of her belongings up to her new bedroom in the attic, she lies down on her bed and as the camera pulls back the window shade is all the way up. It cuts to a wideshot as the camera still pulls back in the rain, and the shade is lower now.
Continuity mistake: After young Sam loses her father in the Northridge earthquake (noted in voiceover), she appears alone on the ball field, at home plate. In the close-up much of the area is in shadow around her, but in the next wideshot the entire area is in sunlight with only the fence/backstop casting thin shadows.
Revealing mistake: After the dance, during the Mercedes vs. Jaguar "race" back to the diner, much of the entire scene takes place at the same intersection of Victory Blvd and Olive Ave, filmed from different angles. Note the Jiffy Lube and Enterprise (cars) on the corners, which are actually across the street from one another.
Visible crew/equipment: When David and Ryan force Austin to participate in the bachelorette 'Dating Game', the CD player sits on the bench beside Austin. When David introduces bachelorette 2, a yellow tape marker suddenly appears on the bench in front of the CD player, which promptly disappears in following shots. (Visible on fullscreen DVD.)
Continuity mistake: At the start, when Sam is reading the text message from Austin stating "Where have u been? We haven't talked...", on the cell display there are two bars in the battery icon in this close-up, but as she replies "We talked this morning", the battery icon is empty in the semi close-up. Then, when she reads his reply in the close-up, once again there are two bars in the icon.
Continuity mistake: At the dance Sam is wearing silver non-platform stilettos with silvery nail polish on her toenails. As soon as Fiona and the "Siamese" twins leave the diner, in the kitchen a much relieved Sam shifts her white gown and she is wearing white platforms and her toenail polish is quite gone now.