Visible crew/equipment: As Sam and Rhonda have Fiona's car confiscated, when Fiona runs out shouting, "I can pay for those parking tickets!" the crew's black mat is laid out on the walkway, but in the overhead shot when she tries to run away that mat is gone. (Visible on fullscreen DVD.) (01:28:10)
Continuity mistake: When Carter is splashed as the twins jump into the pool, only one side of his head/hair is wet. In the next shot, all of his hair is wet. (00:56:50)
Continuity mistake: 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.) (00:57:45)
Visible crew/equipment: At the pool, when Sam brings the salmon plate to Fiona, just as she rushes down the stairs, the shadow of the boom mic and pole is seen moving from right to left, along the grass. (00:06:40)
Visible crew/equipment: When David and Ryan force Austin to sit on the bench and meet the bachelorettes (with 'Dating Game' music playing), the white actor's mark is visible on the ground before Austin covers it with his foot. Also, when David introduces bachelorette 1, then bachelorette 3 and after Mrs. Wells says hi to Ryan, the green actor's T-mark is visible at David's feet. (Visible on fullscreen DVD.) (00:57:20)
Continuity mistake: At Rhonda's house, when Sam says, "You sure do have a knack for taking something simple and making it beautiful," the red bowl is beside her. After Rhonda shows Sam the white gown, the camera pans back toward the table top and the lace mask suddenly and deliberately appears and is leaning against the bowl.
Visible crew/equipment: When Austin is putting up the Cinderella fliers at school, in the first shot as he, David and Ryan walk forward, the blue actor's mark is visible on the floor behind Ryan, where he and David were just standing. (Visible on fullscreen DVD.) (00:52:50)
Continuity mistake: At the start of the pep rally, Mr. Ames takes a seat behind Austin in the close-up. Next shot facing the crowd, when Coach steps up to the stage, Austin's father is gone - his seat is empty, but a couple of shots later Mr. Ames is still there. Additionally, Sam and Carter are also gone in the crowd shot. (01:09:40)
Visible crew/equipment: During the football game, in his close-up when Austin shouts before the hike, "Down, set 28 guarding..." the large white reflector screen is reflected on his helmet. (01:24:00)
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. (00:53:05)
Continuity mistake: When Austin is putting up the Cinderella fliers with Ryan and David, his hair is considerably shorter than the following shots, such as when he goes to the diner and talks to Sam at the counter.
Continuity mistake: When Sam is sitting on the friendship circle you can see that her legs are crossed the entire time. When she texts Austin you see her legs and they are not crossed. In the shots before and after this one her legs are crossed. (00:14:50)
Continuity mistake: When Sam is taking batting practice during school, she hits a ball at Carter's feet. If you look at the way she hits the ball, she pops it up. Then the very next pitch she check swings and crushes the ball to Austin Ames.
Other mistake: When Sam is texting Austin, she gets the reply the split second after she sends her text. There isn't enough time for Austin to read the text and reply.
Continuity mistake: At the beginning of the movie when the younger version of Sam is blowing out her candles, the amount of ice cream in the cup next to her changes within seconds. (00:02:10)
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: During Sam and Austin's dancing outdoors, Sam's hand shifts. In one shot it is completely over his shoulder and in the next shot it is on his shoulder. We see her hand the entire time so there is no time for her to move it without seeing it.
Continuity mistake: After the twins enter the car wash, in the first shot when Gabriella walks through the vertical black cloth strips, with squeegee in hand, she is wearing the large hoop earrings. When it cuts to the next shot, as she shouts, "Bri?," her earrings are suddenly gone. This occurs before Brianna climbs onto Gabriella's shoulders. (01:04:00)
Continuity mistake: When Sam is running away from Austin at the dance, the bottom of her dress is very dirty, it's almost black. When she runs inside and runs up the stairs, her dress is white again. This is confirmed on the commentary.
Audio problem: When the twins are practising in the house pool, Brianna farts and you can hear her say "whoopsie", but her mouth doesn't move. (00:07:10)
Answer: Yes, this happens in most schools. The reason is that students are more likely to pay attention to announcements that are not made by a boring school employee. In many American schools, we have a phenomenon known as "home room". This is a short period usually first thing in the morning that is non-instructional when announcements are made, forms are filled out, and administrivial functions that don't have anything to do with any one class. At schools that don't have this, they have a thing called "study hall" or "independent study" which is a period where you sit in a classroom and work on your assignments, special functions for the school admin. like you are talking about are frequently done at these periods by students who are "working in the office" rather than studying. Then, there are schools that actually have classes in journalism, broadcasting, etc. where this activity would be part of the schoolwork.
Myridon