This was Adams' first British Touring Car Championship race and, being new, he apparently missed the breaking point for the turn and went full speed underneath Plato's rear. The sliding save works because the FWD Chevy accelerates itself out of the slide and into the next turn by getting hard on the gas. Plato slid back one place to second but, thanks to a ruling on Adams' bad stop, the four-second penalty put the veteran back in the lead. It was the first BTCC win for Chevy since 1975.
Anyone else notice that Plato locked up the inside rear of the Lacetti just prior to Adams making contact? I know this is a "new" car for Plato (actually a 2008 model, I believe) so perhaps he wasn't used to the braking power, but to me it looked like Plato slowed down too much rather than Adams missing the braking point altogether.
I'll leave the conspiracy theories about if it was intentional or not to others.
Either way, a fantastic save.