Character mistake: When Aubrey is telling the Bellas that they will practice two hours a day, seven days a week, the board behind her states that on Sundays they have the day off. (00:35:05)
Character mistake: In the scene where Becca and Jesse have a picnic, she tells Jesse that she knew Darth Vader was Luke's father, because "Vader literally means father in German." This is incorrect. However, it does mean father in Dutch. The German word for father is Vater.
Character mistake: At the activities fair, after Benji and Jesse walk away from the Treblemakers, Bumper says "Let's match pitch." Then sings a note. The rest of the Treblemakers harmonize, rather than match the note that Bumper sings. (00:15:40)
Character mistake: When Jesse is talking to Becca about "The Breakfast Club," he tells her that the best song is "Don't You Forget About Me" which was recorded by Simple Minds because Billy Idol didn't want to do it. Steve Schiff and Keith Forsey composed "Don't You..." Billy Idol approached them, requesting to sing the track. Steve Forsey didn't want Idol to do it for the movie, and Forsey personally chose Simple Minds. Idol was eventually allowed to record his version of the song, and it's on his album "Billy Idol - Greatest Hits" as remastered in 2001. He stayed true to the original.
Answer: It wasn't just that she sang a song he likes, she sang arguably the most well-known song from his favorite film in front of a huge crowd of people. It was a public, heartfelt apology rather than the abrupt, private apology she gave earlier.
BaconIsMyBFF