Forum Rider Down and/or notification of minor incidents

I would argue that it was in part my fault as it was my stopping that physically caused the collision

FWIW I was also riding single speed rather than fixed so my brake lights were technically working if we're going down that road again (which we shouldn't)

Pfft, you could have been stopping for any reason from monster pot hole to grandma to injured duck in the road. It's the repsonsibility of the person following to be able to come to a stop suddenly.