I dont think it'll be anything as dramatic as a failed drug test. I'd imagine they were all tested and had the results before they were picked for the show.
I hope George gives Bolo another crack at it but I really cant see it. George is an asshole, no 2 ways about it and he'll definitely pick who he sees to be the weakest UK fighter. As a side note, the new Aus guy is hideously ugly... but I bet he can fight his ass off.
Im really enjoying this season of TUF, its probably the best season for a long time. I do hate George though, he's a total prick. I really hope Pearson smashes him at the finale... cant see it though unfortunately.