The minute Michael said no, I said to my wife "They're going to do all the backstage stuff about changing their minds now, they haven't done that yet this series."
Every series of X Factor there is one occasion of "I think I made the wrong choice", "Lets call them back".
And lo and behold, exactly as I predicated. It was obviously scripted to make the audience feel that they have a say, and build hype for the "underdog" act. Why a no for these guys but a yes for the bells couple, or the elderly dog? It wasn't the greatest drum act ever, but it was better than most of the crap thats got through this series. Clearly a set up.