There was no evidence of any outwards movement by Crawford immediately before, or at the time of the accident, the report said.
The trailing horse, Lemon Honey ridden by Toni Direen, had no chance of avoiding the fallen Elleaye, and Direen was also dislodged.
Champagne Eva was also severely hampered, with its rider losing her side iron and becoming severely unbalanced.
The fallen riders were immediately attended to by paramedics who were in an ambulance following the field, the report said.
Mundy, 26, sustained serious head injuries and was flown to Dunedin Hospital. Her parents, their partners and her closest friends spent time with her before her life support was turned off the following evening.
Her organs were donated.
A leading apprentice, Mundy was a freelance jockey at the Gold Coast Turf Club. She rode 232 winners in her career, including 43 winners during her 24 months on the Gold Coast, and was perhaps the only female South Island jockey to notch up 100 wins as an apprentice.
She was twice named the South Island's leading apprentice.
She returned to New Zealand each holiday racing period to ride the South Island's summer circuit over two months. She had spent Christmas with her family in Westport for the first time in a decade.
Her death was the first of a New Zealand jockey from a race day fall since Sam McRae died, aged 16, in 2005. McRae's foot got caught in stirrups at a Riverton meeting and he was dragged 900m.
Mundy's death has been referred to the coroner and is also being investigated by the police and the Ministry of Business, Innovation and Employment.
The RIU has provided the coroner with the stipendiary steward's report, videos of the race, reports of the racecourse investigator and transcripts of interviews carried out by RIU staff.
About 600 people attended Mundy's funeral service in Westport. Her father Lockey told them his daughter died doing what she loved.
"One minute she was on a horse going 100 miles an hour and the next minute she was asleep.
There's no point asking 'why?' - that's just the way it is. Sometimes the dice rolls, sometimes it's not your day. And for our girl, it wasn't hers.".
- Westport News