The three witches were/are nothing more than lowlife trash. In the states they're called "white trash" by whites, as well as blacks, although the term "trailer trash" is also used. One comment by Jermain (and it wasn't a comment about their colour, as I remember, he said something like "that's what we'd call "white trash") was nothing compared to the dozens of out-and-out bigotted comments from the "white trash" trio.
I think it was a fix that Shilpa won, I don't know how they did it, but I wouldn't put it past Endemol to fix it somehow. As for the booing and cheering, a mate of mine (on the crew at Elstree) reckons that the crowd weren't "told" to do anything, it would have been impossible to implement although the crowd were "selected" a bit more carefully than usual.
Cragiep, you really should brush that huge chip off your shoulder.