Team GB’s Perth-born captain Eve Muirhead took to Twitter to protest over a penalty imposed on her for not releasing the final stone before the red line in their Olympic encounter with Sweden.
The violation allowed their rivals to claim victory, but left a bitter taste for the British team and their coaches.
The curling stones used in Pyeongchang are fitted with a censor that lights up green if the handle is released in time or red if it is not. However there is no other review process in place if a penalty is disputed.
Muirhead, who posted a picture on Twitter which appeared to provide she had let go of the stone before it crossed the line, said: “The red light came on so that’s counted as a hogged rock, so that has to be taken off.
“When you see the replays in the stadium it looks like it was. It’s hard to take and it comes down to inches and millimetres. It’s the first stone I have ever hogged in my life and it comes at a time like that.
“We have had the stone tested and it’s fine so there’s nothing we can do, we have to move on.
“When something like that happens it makes it very tough to take and it’s gutting that it finished that way.”
Team GB coach Glen Howard said: “I’ve only seen one replay and it looks like Eve has let go of the rock prior to the hog line and the light went off.
“Then all they do is question the handle on the rock, and test whether the lights are working properly. The lights were working properly so therefore it becomes a hog line violation.
“The only thing I can think of is Eve has let go of the rock prior to the hog line, it crossed the line and then she happens to just touch it again with her finger on the handle to then activate the light.
“You could call it a double touch. It’s a horrible way to finish the game.”
Cricket, football, rugby and tennis have all made use of video technology in recent years, but its introduction to curling has been resisted by the sport’s governing bodies.
BBC curling commentator Jackie Lockhart, a four-time Olympian, said: “I have never seen that before, especially with the last stone in the last end.
“You have to release the stone clearly before the hogline Sometimes under a little bit of pressure you can hold on to the stone too long. You have to rely on technology. It’s a real sad factor.
“All sports are progressing and we probably have to start looking at using video footage as well. That’s really disappointing. It’s not the way you want it to happen.”
The defeat leaves Eve Muirhead’s rink with three wins out of six so far, with three more round robin matches to come - against Switzerland today, Japan tomorrow and Canada on Wednesday.
The top four sides qualify for the semi-finals.
Meanwhile, curling has become involved in another controversy after reports that Russian bronze medallist Alexander Krushelnitsky had failed a drugs test.
He is said to have tested positive for meldonium, the heart drug that led to tennis star Maria Sharapova receiving a 15-month ban.
A statement from the International Olympics Committee said: “On the one hand it is extremely disappointing when prohibited substances might have been used, but on the other hand it shows the effectiveness of the anti‑doping system, which protects the rights of all the clean athletes.”