Continuity mistake: When Troy's mom tells Troy to get ready for the party, his dad gives him the basketball. In the next shot his dad is still holding the ball. (00:01:15)
Continuity mistake: In the homeroom scene, Ms. Darbus says "Mr. Bolton, I see that your phone was involved so I will see you in detention." and we see a close-up of Troy with both of his hands resting on his cell phone, with one hand ready to close the phone. The camera angle zooms out, and, instead, we see one hand resting on his lap and one hand holding the phone. (00:10:10)
Continuity mistake: When Gabriella is shown Troy on the laptop, dismissing the musical, she begins to cry. She still has wet tear streaks on her face as she looks out the window, but as "When There Was Me and You" begins, her face is dry.
Continuity mistake: When Troy and Gabriella exchange numbers, Troy uses Gabriella's phone to take a photo of himself, but he doesn't press enough, if any buttons to put his number in.
Continuity mistake: Things on Principal Matsui's desk change position between shots, and the cup with the ruler, scissors, etc. vanishes. (00:21:05)
Continuity mistake: The post-callback basketball scene's countdown clock isn't accurate. If you try counting with it, you'll notice that it reaches 0 by the time that the ball's being passed to Troy.
Continuity mistake: When everybody is exiting Ms. Darbus' classroom after the first day back, as Troy and Gabriella talk in the hallway, some of the same people are seen walking out of the classroom twice.
Continuity mistake: During "Stick to the Status Quo", when Martha is singing, things on the table change/move around between shots, particularly the milk carton to her right, which has two straws, then none, then one, then none, then one again. (00:40:00)
Continuity mistake: At the start of "Stick to the Status Quo", when Zeke is singing, the nylon lunch bag opens and closes itself repeatedly, the brown paper bag is either upright or lying on the table, as well as other changes on the table that occur between shots. (00:39:30)
Continuity mistake: When everyone is in home room and they are getting their phones taken away, Troy is shutting his phone in a close up, and then when they show the whole class, his phone is open again.
Continuity mistake: Troy and other members of the basketball team say that the big basketball game is in 2 weeks, and the scholastic decathlon members say that their championship is in 1 week, but near the end of the movie their championships are on the same day. We know Sharpay couldn't have changed it because all she asked to be changed was the call back date.
Continuity mistake: In the song 'Breaking Free,' Troy's microphone constantly jumps from one hand to the other as the shot changes but too quickly for it to be because he moved it.
Continuity mistake: When Sharpay gets french fries dumped on her shirt, her white under shirt has nacho cheese all over it. But in the next scene when she talks to Zeke, her under shirt is clean again.
Continuity mistake: Troy is running down the stairs to get to the audition, his boxers are blue. However when he says " I'll sing with her", his boxers are now white.
Continuity mistake: Near the end, at the end of "Breaking Free" , Gabriella has the mic in one hand, but in the next shot it's in the other hand.
Continuity mistake: Just as Miss Darbus walks onto the stage to announce the auditions have begun, Troy quickly hides behind the curtain. However, when they cut to a farther back view, the curtains aren't moving.
Continuity mistake: In the scene at the beginning when Troy and Gabriella sing "Start Of Something New", Troy takes the mic off the stand. Moments later, at a different angle the mic is back on, then off, then back on.
Continuity mistake: In the locker room, the coach's sandwich goes from his hand to the desk to his hand and switches hands a few times in this scene. It also appears to get bigger and smaller a few times.
Answer: I'm not positive, but that is what I've always assumed.