McBride accepts responsibility
Trainer Charlie McBride insists there was "no collusion and no ulterior motive" behind the embarrassing chain events that led to the wrong horse winning the opening race at Yarmouth on Thursday.
The Newmarket handler thought he had saddled 50-1 shot Mandarin Princess to win the opening two-year-old race at the Norfolk circuit, but it was stablemate Millie's Kiss who passed the post in first place.
Millie's Kiss is a year older than Mandarin Princess and was due to run later on the same card in a race from which she was withdrawn by the Yarmouth stewards.
McBride told Press Association Sport: "It was a complete accident. There was no collusion and no ulterior motive.
"It was human error."
The mistake was discovered after the huge outsider, ridden by John Egan, had overturned the 4-6 favourite Fyre Cay in the six-furlong novice auction stakes for juveniles.
As the weigh-in had been announced, the result was allowed to stand – though but most bookmakers paid out on the first and second horses to have crossed the line.
The British Horseracing Authority will launch an investigation and said it will "determine what steps need to be put in place to prevent it from happening again".
McBride accepted he was on "auto-pilot" and in a "mad rush" to saddle what he thought was Mandarin Princess before the first race of the day at 1.40pm.
He said: "I waiting for the saddle at 1pm in the weighing room. John (Egan) weighed in 1lb over and was in the sauna, and that was why we were late trying to get the saddle.
"We put the saddle on in two minutes flat without even thinking it was the wrong horse.
"She looked sound and then we went straight to the parade ring, where I had 10 or 12 of her owners chatting away to me in the parade ring.
"I never even watched the filly go round (the parade ring) and then watched her canter away.
"When she won, everyone was euphoric and were hugging and kissing and chatting away to me. Even then it still didn't occur to me it was the wrong filly.
"I was too engrossed with the owners, the press, and the presentation of the trophy.
"Even her owners, who see her every week, didn't even notice it was the wrong horse and were patting the filly in the winner's enclosure.
"When you're in a mad rush like that, you go on auto-pilot – you go through the motions."
McBride accepted full responsibility for the Yarmouth fiasco and is expecting to be fined by the BHA.
He said: "There is obviously no excuse for not recognising it was the wrong horse. I know them both inside out and have ridden both horses.
"Every trainer who has contacted me has wished me well and said it was just one of those unfortunate incidents that could have happened to anyone.
"I came over here as a 14-year-old and I'm now 66. I have been in racing all of my life so I'd be disappointed if I was banned for one mistake.
"I expect I will get fined, but it was a human error – as simple as that."
Chief executive Nick Rust confirmed that the BHA will conduct a full and thorough inquiry, but said the Yarmouth case appeared to be a "genuine mistake".
He said: "We frequently hold inquires before races based on intelligence or betting information from the morning of the race.
"On this occasion, there were no suggestions of unusual betting patterns and there was no reason to be concerned.
"It appears to have been a genuine mistake, at this stage, although of course we have to complete our inquiries."
Rust added: "We have procedures on a raceday to try and prevent and ensure that this doesn't happen.
"For example, all horse are micro-chipped – they have been since 1999 – and they are checked into the racecourse stables when they arrive.
They are checked against the microchip to ensure the identity of the horse and are then allocated a specific box in the racecourse stables.
"Many of the runners are then checked. For instance if a horse is coming back a long time off or perhaps they've changed trainers, our veterinary team and our equine welfare and integrity officers have a number of checks to undertake.
"The horses are then led out of the stables to go to the parade ring and it's the responsibility of a trainer to make sure the correct horse turns up in a race.
"It is possible that the wrong horse can be brought into the parade ring.
"There's a small risk of it – this is the first time it's happened in the 18 years that we've had micro-chipping and the various other procedures that we have.
"We undertake a number of checks pre-race, in addition to the scan that happens in the racecourse stables.
"The judge will physically check over the horses and in this case, they were both chestnut fillies and they would have looked appropriate to the description of the horse to the eye."
Rust said the introduction of further technology to reduce the risk of mistaken identity has been discussed, but that it would "involve a seven-figure investment".
Angry punters and bookmakers demanded to know why the 'winner' was not immediately disqualified, with the race declared void.
But Rust told At The Races: "We have to complete our inquiries and examine evidence of videos and interview people again before we disqualify the horse, if all is as it seems.
"We did not want to compound things on the day and we have to draw the line at some point.
"The horse was tested, as is normal, within about half an hour of the race completing.
"On the day we had some other incidents. Unfortunately we had a fatality in one of the subsequent races and the veterinary officer needed to deal with that.
"The stewards needed to hold an inquiry between races, so it took a little bit of time to ensure all of the relevant people were together.
"Obviously the weighed-in signal had been announced. We want to ensure we learn from this in terms of how quickly we can get an announcement out, and we will.
"If all is at it seems, this horse will be disqualified, of course, and the (other) owners will receive their prize-money in due course."