Britain’s Got Talent viewers are convinced that they’ve pieced together how a magician set Simon Cowell on fire on Sunday night's show. Miki Dark left both the judges and audience awestruck as he put the BGT judge’s head in a box, to then set the box on fire.The audience gasped in shock, as Alesha Dixon, 44, and Amanda Holden, 52, stood up from their seats as they feared for Simon’s safety. Hosts Ant McPartlin and Dec Donnelly were also taken aback and they watched on from the side of the stage.