I don't really get this.
They didn't ask for participants to write their names on a list and then put a pin in it. She entered a competition, at a time when it was pretty hard to even get into that competition. And then she won.
I'm sure there's an element of luck; there is with most things in life. But she obviously worked hard during that competition and afterwards, so why do you think she has a duty to soft-soap the BBC if she genuinely feels that their treatment of her was racist?
Should the women on Masterchef who got harrassed by Wallace also put up and shut up, because they were lucky enough to have had the chance to be on TV?