A retired magistrate pulled out into oncoming traffic, hit another vehicle and then plunged through a wall, leaving a woman with severe internal injuries.
Malcolm Lomas, 90, from Cheltenham, was driving home from Cornwall with a front seat passenger when he diverted to Ashley Heath to see a 106-year-old family friend on April 30 last year.
But after initially stopping at a junction, dashcam footage shows how his vehicle moved forward and crashed into an oncoming Toyota being driven by Christopher Gover.
Lomas's Mercedes continued to plough forward even after hitting the Toyota and plunged through a garden wall after his foot 'slipped' from the brake pedal.
Mr Gover had his mother, Patricia Gover and her young grandson with him in the car at the time.
Malcolm Lomas, 90, from Cheltenham, was driving home from Cornwall when the crash occurred
Lomas, pictured outside court, admitted causing serious injury through careless or inconsiderate driving
Mrs Gover was taken to hospital with what she suspected were some broken ribs but which later turned out to be much more serious. He internal injuries were so bad that she still suffers from physical and mental health problems, a court heard.
Lomas pleaded guilty to causing serious injury by careless or inconsiderate driving - but was not banned from the road.
A judge disqualified him from driving until he passes a test, should he decide to take one, and fined him a total of £5,103 - leaving the door open for the 90-year-old to return to the road.
The former magistrate found himself in the dock following the accident in Horton Road, Ashley Heath, near Bournemouth in Dorset on April 30 last year.
Magistrates heard that Mrs Gover had been left without a proper immune system due to suffering a severely ruptured spleen, putting her at risk of infection for the rest of her life.
But after Lomas told the court he had voluntarily given up his driving licence because of what had happened, judges decided against giving him a custodial sentence and instead gave him the fine.
Speaking after the case, Mrs Gover, from Southampton, said she found it hard to deal with the fact Lomas had not been prevented from driving again.
She added: 'I struggle every day with physical and psychological problems after the accident. In fact, I am sat here crying about the outcome.'
Lomas, 90, initially stopped at the junction before moving forward and colliding with the Toyota
Mrs Gover remembered seeing a Mercedes coming towards the car she was in before the two collided
Prosecuting, Sue Gethin said Mrs Gover remembered seeing a Mercedes coming towards the car she was in before the two collided.
Recalling her grandson screaming, she said she managed to get out of the car but was in severe pain.
She was taken by ambulance to hospital, where it emerged that her spleen had been very badly damaged and she required surgery. The damage was so bad that she has been left without an immune system, meaning she now has to carry antibiotics all the time.
The accident happened just before 1.24pm. Lomas told police he believed his foot had slipped from the brake pedal, causing his car to hit the Toyota and crash through the brick wall of a house opposite and into a stationary car there.
Ms Gethin said: 'He said he was wearing shoes with little grip and that he wouldn't normally wear. Never in his long driving career had this happened before.
'He was mortified that the lady suffered internal injuries.'
Lomas's Mercedes continued to plough forward even after hitting the Toyota and plunged through a garden wall after his foot 'slipped' from the brake pedal
Lomas told magistrates that he accepted, without equivocation, that he was to blame for the accident
The prosecutor added that Lomas said he was physically fit, going cycling and swimming, and he insisted that he was cognitively okay.
But she said he made an unsafe manoeuvre that caused serious injury.
Lomas told magistrates that he accepted, without equivocation, that he was to blame for the accident.
He said he had been driving for 65 to 66 years and had never been involved in an accident causing serious injury or for which he had been found to have committed an offence.
He added: 'In view of my age, I've asked myself about my competence to drive. I had an eyesight test and neurological investigation - a brain scan and cognitive test. No abnormal features were detected.'
Dash cam footage from the Toyota was played in court, showing the Mercedes moving slowly forward from the junction and hitting the oncoming vehicle.
Lomas said: 'It backs my view, that my foot unconsciously slipped off the brake pedal.'
He said he profoundly regretted that it happened, was severely remorseful and offered his sympathy to Mrs Gover. He said he understood that she might question his fitness to drive.
As a result of the accident, he said that a year ago he voluntarily surrendered his driving licence.
In the UK, drivers of 70 or over must renew their licence every three years but there are no laws restricting the age people can drive until.
