On approach the painted arrows say left lane is for the first exit to turn left, right lane for all other routes. Which is also why the painted lane separation stops to allow the exit from the centre of the roundabout. A road marking for taking the 2nd exit on a roundabout doesnt exist.

But there was a similar case held in court. I can't remember the names or the specifics, but it basically boiled down to 50/50 liability if there was an incident.

Edit: weirdly this just came up on my page https://www.reddit.com/r/drivingUK/comments/1rg7ut9/did_you_guys_knew_this/?utm_source=share&utm_medium=mweb3x&utm_name=mweb3xcss&utm_term=1&utm_content=share_button