I'm not sure they were racing anyone, even though the underpass has been described as a race track, and they may just have been speeding, but you raise a good point Woody. I wonder if the police will check some of the previous cameras, and see if there was another car that sped off when they say what happened.
As to the 12 months served; he'd have got time served on remand set against his sentence, so at only 18 months required, he wouldn't have been in there very long. This leads on to wondering why if they weren't banged up on the first offence, rather than getting 25 cautions first, then the police would have the resources to do their job properly.