A mum-of-two died after she ‘stepped out of a moving car’ on the motorway and was hit by oncoming traffic.
Dominique Worrall, 32, had been arguing with her boyfriend Terry Dunne minutes before the incident on February 20 last year, an inquest heard.
CCTV footage showed her getting out in the middle of the M20 and being hit by ‘several vehicles’.
Ms Worrall died of multiple injuries after she was struck at around 6.05pm between junctions 10 and 9.
A detective said the footage clearly showed she came out ‘on own free will’.
Mr Dunne did not stop the car, and instead handed himself into police the next day.
He was initially arrested on suspicion of murder, but all charges have since been dropped.
DS Ross Gurden told the inquest the couple had been drinking at Camber Sands caravan park and tensions were high due to a dispute over an ex-partner.
It had also been raining and there was a heavy build-up of traffic.
A previous claim of domestic violence against Mr Dunne in 2017 was also brought up during the inquest.
The coroner heard she told the 999 operator: ‘Domestic violence, please come now’ and had suffered serious facial injuries.
Mr Dunne was arrested for grievous bodily harm but no further action was take due to insufficient evidence
Ms Worrall had been under the care of mental health teams and had previously attempted suicide.
She was also diagnosed with Emotionally Unstable Personality Disorder, alcohol misuse, and probable bipolar disorder in January 2018.
Concluding the inquest, assistant coroner Geoffrey Smith gave a verdict of misadventure.
He said: ‘No one will know what happened in that car.
‘Mr Dunne denies any involvement in her death and officers say there is no third party involvement.
‘What cannot be doubted is she fell from the vehicle travelling at speed and that killed her.’
He added cocaine was found in her system and that she had also been drinking.
Dominique’s mother Loretta Petrucci said after the inquest: ‘I have so many unanswered questions.
‘I can’t mourn my daughter because nothing makes sense to me.
‘Why didn’t he stop? That was my daughter and he was supposed to love her.
‘You would stop for an animal.’