US Edition Sean Carter, 42, was driving through Nottinghamshire when he witnessed a crash in which a Citroen Saxo rolled over three times.
He pulled over, helped the young driver out of the wreckage, and then invited him to sit in his passenger seat to shelter from the cold.
However, when paramedics arrived they said the injured man might have spinal injuries. In case that was so, they needed to get him into their ambulance while in a horizontal position so would need to have the roof removed from car.
Mr Carter, of Ripley, Derbyshire, had to stand by and watch as firefighters used heavy cutting gear to open up his Ford Focus and extract the driver.
"I just watched in horror as the firefighters started smashing the windows in," he recalled.
"They they moved on to the roof. They dissected it at the sides and the back and then folded the roof back onto the bonnet," he recalled.
When Mr Carter's car was declared a right-off he expected the injured driver's insurance company to pay out.
But the bill was eventually paid by his own company. As a result he lost his no claims bonus and is still trying to recoup the cost of a hire car. He estimates that he is £1,000 out of pocket.
It emerged after the accident that the Saxo driver was free of spinal injuries and well enough to leave hospital the following day.
A spokesman for Nottinghamshire Fire and Rescue Service said the destruction of Mr Carter's car was unavoidable.
"In situations like this we have to remove the injured person horizontally for safety purposes."