It appears to have been heard in a crown court which I think means a trial by jury. Perhaps they are just being pragmatic in the knowledge that, once the seriousness of a dangerous driving charge is made clear to them, juries just won't convict.
dangerous driving requires proof that the driver's behaviour was ``far below'' that expected. Given driving blinded by sun for 30 seconds isn't careless you need to be pretty spectacularly bad to be dangerous.
Does anyone know why the prosecution dropped the dangerous driving charge?