Grace v Tanner (2003)
A motorcyclist was proceeding South on a dual carriageway. A car driver was proceeding south on the inside lane and the motorcyclist was in the outside lane. Both entered the roundabout and retained their road positions. The car went past the required exit and continued on. The motorcyclist turned left at the exit from the roundabout and collided with the car which was continuing on around the roundabout.
Motorcyclist 50% to blame Car Driver 50% to blame
A link to the full Judgement can be found here.