Does Justin lip sync in his 3D movie?

I was at the taping of Justin Bieber's 3D concert in New York City and when he sang "Somebody to Love," his mic pack detached from his pants because he was hanging upside down. Now if he was lip syncing, his voice would have continued... but his part of the song went totally silent! Luckily, Justin quickly grabbed another mic and kept performing like a true pro!