If they were actually there on the red carpet, then why would anyone think that they weren't on stage? Thomas has also said in an a radio interview when asked about if they have ever sent anyone else up on stage for them. Saying something along the lines of "why would anyone want to give up the experience of being up there in front of the crowd."

As for the question of whether they were actually doing anything up there other than pretending to hit buttons, is another issue.