In 2009, Mike Baillon was filmed smashing the windows of a 4×4 to arrest the driver, 71, who refused to stop despite a 17-minute chase.
The video was leaked and viewed more than 30m times online.
A tribunal ruled he was constructively dismissed. He is now seeking damages.
Mr Baillon, then 42, was one of two traffic officers who pulled over Robert Whatley for not wearing a seat belt after following him along country roads near Usk in Monmouthshire, south Wales, in 2009.
But Mr Whatley drove away before they had finished dealing with him.
They pursued him for 17 minutes along country lanes.
When Mr Whatley finally stopped his Range Rover, the video showed Mr Baillon running up to the driver's door with his baton drawn and bashing the window 15 times until it smashed.
While Mr Baillon was subsequently found not guilty of misconduct, the video of the incident was leaked and put on the internet.
Despite the difficulties he experienced at work, his solicitor Nick Smith said Mr Baillon had “hung on for grim death” to his career.
But he “snapped” and quit, unable to withstand being the butt of colleagues' jokes any longer.
Mr Baillon had been a traffic officer for 11 years after joining the Gwent force five years before but had been moved after the incident in 2009.
'A huge source of therapy'
Mr Smith said Mr Baillon was unhappy to be taken off frontline duty and believed Gwent Police had handled his complaints badly.
Monday's hearing in Cardiff on Monday heard arguments about what Mr Baillon should be entitled to.
Mr Baillon, who set up his own business after leaving the force, is claiming lost earnings and pension entitlements.
His solicitor described these as “a very big sum” although exact figures were not disclosed at the hearing.
Mr Smith said: “We're talking about a man who would have made sergeant.
“This was a man who was wounded to his core by the way he was treated by his employers.”
He argued that rejoining the police service would have been a difficult proposition and starting his own business was the “best way” to mitigate any loss of income as a result of his resignation.
The woodturning business Mr Baillon set up had proved “a huge source of therapy for a man who has been abused by his employer”.
Mr Smith added: “He was a hugely admired police officer who'd been through hell.”
A decision on how much Mr Baillon will be awarded is expected by next February.
Solicitors for Gwent Police said the force would considering appealing against any award because some aspects of the case had “not been dealt with reasonably”.