The High Court has ruled that the fall which left flat jockey Frederik Tylicki with life-changing injuries resulted from negligent riding from fellow jockey Graham Gibbons.
Tylicki, 35, was trampled after falling from his mount, Nellie Deen, during the 3.20pm race at Kempton Park in Surrey on October 31 2016.
Left partially paralysed and now a wheelchair user, Tylicki sued fellow Flat rider Gibbons, 39, in a bid to hold him liable over the incident in the one-mile fillies' maiden.
His lawyers argued that Gibbons, who denied riding negligently, manoeuvred his horse Madame Butterfly into the path of Tylicki's mount, which was running into a gap between his horse and the edge of the track as they turned on to the home straight.
In a judgment on Tuesday, Judge Karen Walden-Smith found in Tylicki's favour, ruling that Mr Gibbons "had a reckless disregard for Mr Tylicki's safety".
The judge ruled that it was more likely than not that Mr Gibbons was aware of Mr Tylicki's presence before the fall.
She continued: "If Mr Gibbons was not aware of Nellie Deen's presence he clearly should have been.
"He was considered to be a highly skilled and talented jockey, and a jockey, particularly riding at this very high level, both needs to be, and is, able to assess and reassess the constantly changing racing conditions, which includes the positioning of other horses that are nearby, in order to be able to adjust their own riding and tactics."
During a five-day hearing last month, the High Court in London heard evidence from both jockeys.
Tylicki told the court that he shouted out "Gibbo" moments before he fell.
He said: "It was a shout for survival, to be honest, because I knew what was going to happen next, but there was no response."
Gibbons denied trying to block Tylicki's progress.
"When Freddy shouted at me I looked over my right shoulder immediately and I was surprised and shocked that there was a horse there," he said.
Judge Walden-Smith said she had to decide whether the fall was "a very unfortunate accident with tragic consequences" or whether Mr Gibbons was liable for his fellow jockey's injuries.
Finding Gibbons liable, she ruled: "In my judgment, during this spell of riding… Mr Gibbons had a reckless disregard for Mr Tylicki's safety.
"Mr Gibbons knew, or at the very least ought to have known, that Mr Tylicki was inside on the rail and had moved up to within a half-length of Madame Butterfly.
"He exerted real pressure on the right-hand rein of Madame Butterfly in order to bring her across Nellie Deen's racing line and did not stop bringing her in close to the rail even after the first collision."
Judge Walden-Smith said Mr Gibbons' actions "were not mere lapses or errors of judgment" and were "a course of action that carried over a number of seconds".
She continued: "While that might, in some circumstances, be considered a short period of time… this was a sufficient period of time for a skilled jockey to make decisions."
The judge concluded that her findings only related to this case and did not set a precedent.
In a statement after the judgment, Tylicki said he was "delighted".
He said: "Today's result has finally provided me with closure and I look forward to putting this all behind me and moving on with my life.
"I hope, though, that this judgment acts as a reminder that competing in a dangerous sport like horseracing is no justification for competing with a reckless disregard for the safety of your fellow competitors."
Responding to the judgment, the British Horseracing Authority said in a statement: "The BHA will consider today's High Court judgement in detail and carefully assess what implications it may hold for British racing, in discussion with industry stakeholders.
"The full transcript of the hearing will also allow us to consider any of the other relevant matters which were raised over the course of the hearing."
Dale Gibson, interim chief executive of the Professional Jockeys Association, said: "Our concerns at this moment are with two former members who we have great sympathy for, particularly at this time. We will carefully read the full judgment before making any further comment."