Jean Forsyth died when Martin Muir smashed into her husband Robert’s Citroen C3 in August 2013.

Paisley Sheriff Court heard that experts where unable to say for sure what speed Muir was doing in his Skoda Octavia Victor Rally Sport, which was fitted with a spoiler.

The force of the crash was so severe that it thrust the Forsyths’ Citroen backwards and flipped it onto its side during the crash, which occurred on a country road near Neilston, East Renfrewshire, Mrs Fosyth, 84, was airlifted to hospital for treatment but sadly passed away from chest injuries she sustained in the collision.

Muir was charged with causing her death by driving without due care and attention.

Prosecutors claimed Muir, of Johnstone, Renfrewshire, failed to keep proper control of his car, made his wheels lock while braking, and crossed over onto the wrong side of the road, hitting the Forsyths’ car and killing Jean.

But yesterday a jury cleared him of all blame over her death, taking one hour and nineteen minutes to find him not guilty by majority verdict.

He had earlier told the court that endured sleepless nights over his involvement in her death.

The 27-year-old said: “I don’t sleep - the doctor put me on anti-depressants.

“I wake up regularly and I have flashbacks. It’s really quite bad.” Muir also said the crash put him off driving so much he stopped driving altogether.

And he said he only got back behind the wheel again when the person who drove him to his work in Rosyth, where he builds aircraft carriers, fell ill.

He said he saw the Forsyths’ vehicle “at the last minute” and had to make a “split-second decision” about what to do.

His daughter Lucy, six, and step-daughter Keira, 10, were in the vehicle at the time and he said he was “trying to be as safe as possible” with his driving as a result.

Muir also said that, when he saw the Forsyths’ vehicle, he had to decide if he was going to crash into a wall that was on his left and possibly flip his own car or try and drive passed them into a field.

He said he tried to steer his car into the field but hit the Forsyths, killing Jean, the secretary for the Scottish Women’s Rural Institute Magazine, and injuring Robert, 94.

He explained: “I didn’t know his name at the time but I know it now - Mr Forsyth.

“I could see his face. He didn’t do anything. No braking, no evasion, no nothing. I chose to go into the field. He 100 per cent froze.

He didn’t do anything at all. I don’t think he applied the brakes or anything.” He said that, after the smash, he got out the car, made sure the children were safe, called 999 and went to see how the Forsyths were.

He said he could see Mr Forsyth did not have his seatbelt on and was slumped over his wife.

Mr Forsyth, a retired architect of Uplawmoor, East Renfrewshire, told the court he was doing between 20 and 25-miles-per-hour and thought Muir must have been going fast as his car was thrust back and flipped on it side.

He sobbed as he told the jury that “a deathly silence” fell on his car after the crash, which left him with bruising and killed his wife of over 60 years.

They had spent the day delivering copies of the Scottish Women’s Rural Institute magazine, which Mrs Forsyth had done for 25 years, and were returning to their home when she was killed.