I doubt for one minute that the female motorist, the teacher, left her home that evening intending to kill somebody. The police investigation and the Procurator Fiscal came to a conclusion that she should be prosecuted for careless driving, which she was. She's been found guilty and sentenced. As tragic as the accident is, it would appear that it was an accident. She's done something that ultimately wasn't the right thing to do and she and Jon have paid a price for that. I'm not trying to suggest for a minute that her anguish and regret and guilt which she will have to live with every day of her life is as high as the price that Jon and his wife have paid, but it's an accident. I would suggest that most people have done something at least once in their driving career that, if they were honest with themselves, fell below the normal standard of driving. And presumably, you/they got away with it, nothing happened, you didn't hit anybody or anything either by good luck or because there wasn't anybody nearby to hit.
This whole incident would be completely different if it was as a result of a driving incident whereby somebody was out driving like a nutter, being chased or just somebody that drives like sh1t all the time, or somebody's that's p1ssed in which case the charges would have been different and the offender would, rightly, be starting a lengthy custodial sentence now. But this appears to be Mrs Joe Decent who has made a mistake and will spend the rest of her life regretting it probably.
Its desperately sad and nobody comes out of this well.