Champion jockey Tony McCoy is among nine jockeys who have been suspended for 10 days for failing to observe a race-stop flag at Wetherby.
The Betfair Supports Spinal Research Handicap Hurdle was declared a void race after Ashburton Lad pulled up with a broken leg.
But McCoy, Brian Hughes, Graham Lee and Danny Cook all failed to stop.
Denis O'Regan, Alex Voy, Jonathon Bewley, Paddy Brennan and Brian Toomey have also been given suspensions.
The suspensions will run between 26 October and 4 November.
Ashburton Lad pulled up injured on the first circuit, causing head groundsman Ian Ward to wave a yellow flag, however the British Horseracing Authority (BHA) has asked for an explanation because the stricken horse was not in the path of the runners.
Most of the runners in the race, including 2010 BBC Sports Personality of the Year McCoy, carried on, with Cunning Clarets, ridden by Hughes, first past the post.
The three other jockeys in the race - Dougie Costello, Tom Messenger and Campbell Gillies - were not involved in the incident.
Costello, on Favours Brave, pulled up, Messenger's Glorybe refused to start and Gillies was on board Ashburton Lad.
Wetherby racecourse chief executive Jonjo Sanderson said: "Ian was concerned that the runners would not be able to get past the stricken horse and he made a judgment call.
"In his role as head groundsman he is well within his rights to make such a call.
"It is in his remit to make such a decision. He has held his current position for at least four years. Ian has not made a mistake, it was a judgment call."
Cook, who was on board Charlie Crab, said: "I'm very annoyed and very frustrated.
"There were flags all over the place and no-one knew what they were doing.
"I saw a yellow flag but then a bit further on I saw a hazard flag so we carried on as the hurdle was not dolled out.
"He (Ward) should have been further out so we could all see what was happening clearly."
McCoy and the other guilty jockeys refused to comment.
In a maiden hurdle also at Lingfield, jockey Jack Salmon was suspended for 10 days after stewards adjudged he should have pulled up Alaskan Prince earlier than the third flight as his mount appeared to have gone lame.
Meanwhile, Natalia Gemelova became the third jockey to be banned for failing to follow the BHA's stricter whip rules.
The 34-year-old was given a seven-day suspension as a result of her ride on second-placed For Life, where she used the whip seven times in the last furlong.
Under the new rules, a maximum of seven strikes are allowed during a Flat race, and no more than five during the final furlong.
Two more bans for flouting the new regulations followed on Wednesday with Pat Cosgrave and William Buick both suspended for five days after they were found to have struck their mounts eight times at Lingfield and Kempton respectively.