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.
Other mistake: During the pep rally scene, when Shelby is staging the play, Gabriella comes out wearing a bridal gown. A couple of seconds later, she comes out wearing the "diner girl" outfit, complete with roller skates. There was not enough time for her to change so quickly.
Other mistake: When Conner is setting the time for Sam to be back at the diner by midnight, the phone isn't on. (00:32:47)
Answer: That song is "Hear You Me", by Jimmy Eat World.
moviemogul