but which although negligent would make no difference to the prosecution of any car driver involved in an accident...
Really? That would be disappointing. I would have thought that a cyclist breaking the law by failing to display lights would make it very difficult to prosecute a motorist involved in such an accident unless their behaviour was also negligent.
The only accident I've been involved in was one in which a driver pulled out in front of me from the left and I went over the bonnet, leaving me with a nasty facial injury. It was under street lights, I was wearing a high-vis vest and displaying lights. The driver was not prosecuted (with my agreement) on the basis that a prosecution would serve no significant purpose -- lesson learnt. I doubt our tie-down pilot will make the same mistake again, either, but it seems the ARE has more time on its hands than the CPS.