At least one punter backed a winner at 999-1 after it had already crossed the line on Monday while others lost a combined total of nearly £43,000 at short odds after a three-way photo-finish at Carlisle in which the winner appeared to many observers to have finished second at best.

Ventura Dragon, the 5-4 favourite for the five-furlong novice event for two-year-olds which opened the card, made significant ground against the far rail in the closing stages and flashed across the winning line locked in battle with Sayaady, a 10-1 chance. Magic Mark, at 9-2, was also involved in the finish towards the middle of the track, but the initial impression of many viewers was that Sayaady had just held on.

This belief was apparently confirmed by a freeze-frame of the finish shown on the Racing UK channel moments later, in which Sayaady’s nose seemed to be in front.

Almost £25,000 was staked on Sayaady on the Betfair betting exchange at its minimum price of 1.01 – equivalent to 100-1 on – during the race, and another £19,500 at the same price after the horses had crossed the line, before the judge announced that Ventura Dragon had actually won the race by a nose.

At least one bet of less than £1 was matched on Ventura Dragon at the maximum price of 1000 (or 999-1) before the result was declared, with other bets at 120 (119-1) and 100 (99-1).

The total of just under £43,000 lost on Seyaady at 1.01 places him ninth in the all-time list of expensive short-priced losers on Betfair since the exchange launched in 2000. The most expensive to date was Kay Gee Be, who was nailed on the line in a race at Nottingham in 2011 after more than £200,000 had been staked on him to win at 1.01.

Tim Palin, the director of racing for Ventura Dragon’s owner, Middleham Park Racing, was one of many to be deceived by the close finish.

“It did look like he was finding it too sharp again,” Palin said. “I thought he was running on nicely for third and then I thought he might get second.

“I was watching it at Doncaster Sales and, when they crossed the line, I thought we were second at best, so it was a very nice surprise when I heard the result.”