I-Like-To-Bike

Is anyone aware of the number of investigations of bicycle collisions (involving a serious injury or fatality) that have been significantly aided by recovery of a video recording device from the injured/killed bicyclist? I suspect the number and/or percentage of such investigations "helped" in any significant manner is either zero or infinitesimally small. Perhaps it might be useful in establishing time of incident, but so too a phone in the pocket of bicyclist might reveal that info.