Kevin Hart left the scene of his horror car smash last month while his two friends remained trapped in the vehicle, according to the crash report.
New details have emerged following the accident, with law enforcement sources telling TMZ on Thursday that 'none of the 3 people in the car were wearing seat belts'.
Hart, 40, had to have his spine fused back together after breaking it in three places when his 1970 Plymouth Barracuda barreled through a fence on Mulholland Highway in Malibu in September.
Now it has been revealed driver Jared Black was using a handsfree device for his phone during the accident and that his 'sudden acceleration and loss of control' caused the crash.
The determination came after law enforcement reportedly stripped down Hart's vintage car and found it 'did not have any mechanical issues' and that the crash was caused by 'driver error'.
But they did find extensive bodywork including adding sports tires and a 6.4L Hemi V-8 engine. The car was reportedly without an anti-lock braking system.
The report states: 'There were fold and crease marks on the belt surfaces consistent with being folded and tucked into the seats and no indicators of occupant loading were present.'
If they had been worn, police add: 'They were being worn improperly due to excessive slack in the belts.'
Also in the vehicle was the 40-year-old's trainer Rebecca Broxterman. She is said to have been found facing the windshield between the right passenger seat and the roof. The report states the car was 'not outfitted to carry rear seat passengers'.
Hart, who had plastic storage boxes to replace the backseats, told TMZ: 'I have nothing but love for Jared and wish him and Rebecca a speedy recovery.'
However the site also said their sources have stated there will be 'multiple lawsuit[s] stemming from the crash'.