Police said it appeared that Alexander Neil was out of the vehicle directing his 85-year-old wife Bertha back into a parking space when the accident happened.
Vehicle experts yesterday examined the couple's automatic Renault 25 car as Mrs Neil was being comforted at her home in Ickford near Thame, Oxfordshire.
Police are appealing for witnesses to the accident, which happened at the Budgen's supermarket in Thame at about 1pm on Saturday.
Yesterday, neighbours paid tribute to Mr Neil for his work in the community and told how his wife had recently returned to driving after his sight deteriorated.
Joyce Plested, 72, said: "When his eyesight started to fail, she got back behind the wheel. Eighty-five is a big age to be driving a car.
"If they had been in a road accident, it would have been easier, but she caused it. I don't think she'll ever get over it."She said Mr Neil had taught his wife of 58 years to drive when they were courting.
Mr Neil was born and raised in Ickford and followed his father into running the local dairy farm before retiring 10 years ago. He and his wife had no children. The longest-standing parish councillor, with 54 years' service, he had helped build the village hall which stands opposite the couple's home in 1950.
He was also president of the village football club and founder of the traditional annual tug o'war against the nearby village of Tiddington.
Mrs Neil was yesterday being comforted by family friend Ron Roberts.
He said: "She is very much in shock. It is a terrible thing. Everyone in Ickford knew him and the phone has not stopped ringing."Reuse content