Why are they wasting money investigating?
Put Police officers there & convict the drivers who don't know the rules, along with the cyclists on the pavement, it's kin simple.
It isn't remotely simple, and they are right to be investigating.
While there is no doubt whatsoever that those drivers were seriously at fault, when it happens so often at one crossing, there is something not right in the design of the roads and/or crossing.
Just punishing those who have driven badly there isn't the answer to making it safer in the long term. They should of course be punished, but that won't significantly affect the likelihood of others doing similar. Maybe they need speed cameras, maybe they need a change to the speed limit, maybe speed bumps. I don't know, but
something needs to change, and the investigation should give some indication as to what.,