Six Nations bosses have opened an investigation into the chaotic scenes at the end of the France-Wales game in Paris on Saturday.
Wales' interim head coach Rob Howley said the "integrity of the game had been brought into disrepute" after France replacement prop Uini Atonio went off for a head injury assessment, with starting tighthead Rabah Slimani then returning during a remarkable 20 minutes of second-half stoppage time.
Slimani had earlier been replaced but the France team doctor insisted that Atonio needed an HIA, therefore allowing Slimani to go back on as France laid siege to Wales' line through a series of scrums.
Launching an investigation into the incident, a Six Nations Rugby statement, issued on Sunday, read: "SNRL is aware of concerns about the head injury assessment that took place towards the end of the match and is looking into the matter.
"No further comments will be made until the closing of the citing window and the conclusion of the enquiry."
Wales conceded a try and 100th-minute conversion to lose 20-18 at the Stade de France and centre Jonathan Davies claimed the events "just didn't seem right".
Davies said: "It was a very long extra time, if you call it that. It's a tough pill to swallow. It was disappointing how it ended. Of course, if the prop is complaining about a head injury, player welfare is important. It just didn't seem right, in my opinion."
Howley, meanwhile, did not hold back in his assessment of what he felt took place.
"What happened in the last 10 minutes of that game shouldn't ever happen again on an international rugby field," he said. "The process leading up to the change of the French tighthead, the way that occurred, we love our game too much to have those decisions. It is hugely disappointing.
"The process that occurred prior to him warming up before going back on, one of their (France's) coaches went outside the technical area, had a word with their doctor and within a minute of that, he went on and took their tighthead off.
"The evidence suggests that it's not in the integrity of our game. The referee (Englishman Wayne Barnes) is told an HIA needs to take place, and he trusts that information. It wasn't his fault in the last 10 minutes. He has listened to a medic."
France - whose victory saw them finish third in the final Six Nations standings above fifth-placed Wales - could face disciplinary action if anything is proven against them.
Howley added: "We will look over the whole footage. A lot of it is on microphone as well. It is pretty obvious what happened. There is a technical area, and you are not allowed outside that technical area. Someone has come outside and the doctor has gone on to the field at a break in play. That is outside the laws of the game."
Asked to confirm that Wales had seen an official leave the technical area, brief the doctor and then the doctor run on to the field without going on to treat anybody, Howley said: "Yes. And in between that you can hear Wayne Barnes ask him (Atonio) if he's okay, and the player says 'I've got a sore back, I'm okay' and then the doctor comes on and the player goes off.
"I don't know what can be done because it is about the trust between management and referee. There is evidence to suggest the integrity of the game has been brought into disrepute."
Ultimately, Wales were left to reflect on a third defeat of the tournament and their worst Six Nations position since 2007.
Six Leigh Halfpenny penalties had put them in pole position to win the game, but 20 minutes of added time that also included Wales prop Samson Lee being sin-binned, then took centre-stage.
Reflecting on the tournament, Davies said: "I think we've shown in parts a lot of very good things. But you look at the England game - the end of that - the second half in Scotland and the start against France (Wales trailed 10-0 after 15 minutes), it just shows how important it is you play for 80 minutes.
"You can't switch off. We didn't come out of the blocks, and France did. There are a lot of positives to take away from the tournament, but there are also a lot of things we need to work on."