Mariah Carey's GMA performance sparks another lipsyncing debate...

Mariah Carey recently performed 'With You' on Good Morning America in promotion of her new album 'Caution.' There was quite a debate online as to whether she was lipsyncing or not. OK, so hasn't this been a debate for like the past 10 years now? My honest opinion? I think these were pre-recorded vocals mixed in with some live ones. The vocals were a bit different from the recording version and other live performances. What do you think?