It could very well be that there are many more pedestrian accidents due to hybrids in EV mode while the pedestrian death rate falls dramatically. I would expect most pedestrian hits at typical EV speeds (under 20 miles per hour, and not the max possible 42? MPH) to not result in death, even if severe injuries are incurred.

Note that I am against adding noisemakers to EV running vehicles, unless a proven connection can be shown that this would make a real, substantial enhancement to pedestrian safety. The death rate decrease just doesn't demonstrate any conclusive connection.

-- Alan