Altering the balls by way of camera trickery, which would be a masterstroke in itself, is the only way I could think of to fake it.
The program that followed his prediction was great too. I would love to see how he primed the minds of the people on their way to the show. I don't believe it was set up but I know for definite that I would have responded differently to the way some of his subjects did.
Roll on 9pm tonight.
Yeah, everyone thinks that about themselves TBH 
That's my point. If I was at that show, I would have experienced whatever they were subjected to beforehand, subliminally altering my thoughts.
The best example was the woman who was asked to pick the envelope with the cheque in it. Just before she made her final decision, she read out a letter, written beforehand by Brown, stating that she would not change her mind. To beat him, all she had to do was switch envelopes, irrespective of whether the cheque was there or not. She stuck with the same envelope and it didn't contain the cheque.
How you can influence a mind to make such mistakes is something special.