As a mother touching 50, a solicitor with experience of dealing with the CPS, educated in and very familiar with SW London, and (as it happens) epilepsy diagnosed in my mid-30s: @hohohomey has it.
People want to believe in doctors, police officers, solicitors, the CPS. They are the infrastructure of a society that is orderly and in which justice might exist. It makes us feel secure. Reality is very, very different. The law doesn’t set the framework for moral justice; in areas such as this it merely allocates responsibility.
Uncertainty is being exploited in favour of the driver and to the detriment of the parents. It happens all the time. The most bitter of pills for the bereaved parents to have to swallow.
Separately, I’m shocked and disheartened by the naive vociferous defence of the driver on this thread. Perhaps they are vested parties; perhaps these posters see themselves in her more than the parents of the deceased girls.