A 70-year-old spent his final days in pain after his jaw was broken in a road rage attack by an off-duty police officer, a misconduct panel heard.
Peter Burgum died from unrelated causes after being punched by Stuart Box, a PC with Avon and Somerset police, who then fled the scene last April.
Mr Burgum’s wife Caroline said memories of her husband are “indelibly marked” by what happened.
Mr Box admitted gross misconduct but faced no criminal charges.
A panel ruled that he would have been sacked for gross misconduct if he had not already resigned.
The incident unfolded after Mr Burgum overtook the cycling off-duty officer in Frampton Cotterell, the Local Democracy Reporting Service said.
Mr Box banged on the side of the car and hit the wing mirror when Mr Burgum braked. He then slapped Mr Burgum who then took out his phone to film the incident, the panel heard.
The officer claimed he had been hit first as he grabbed the phone and threw it over a fence, before punching Mr Burgum and leaving the scene.
Representing Avon and Somerset Police, barrister Elliot Gold said the officer was trying to escape responsibility but he was identified from dashcam footage.
Mr Burgum’s jaw was broken in two places, requiring surgery that left him unable to eat solid foods.
Mr Gold said: “The consequences were that Mr and Mrs Burgums’ last weeks together were affected in the most adverse way.
“Mrs Burgum has had insomnia, nightmares and flashbacks. Her memories of the last weeks with her husband have been indelibly marked.”
Police Federation representative Andy Roebuck said the former officer had expressed remorse and “could only apologise” for what happened.
Panel chair Stephanie Beazley said: “Had he still been serving his position would have been untenable. He would have been dismissed without notice.”