Referee Chris White has apologised to Wales over the "misunderstanding" at the end of Saturday's Six Nations defeat to Italy in Rome.
Gareth Thomas leads the Wales protests with Chris White in Rome
Wales were incensed when White blew for time after they had kicked into touch believing there was time for a lineout.
"I have apologised to the Wales coaching and playing staff for the misunderstanding," said White.
"I would like to thank them for the good grace with which my apology was accepted."
Wales were awarded a penalty near the end of the game and decided to kick for touch and go for a match-winning try instead of taking a shot at goal to secure a draw.
White was heard telling Wales' James Hook there were 10 seconds left to play, and so the centre assumed they had time for one final play.
But as Wales prepared for the lineout, White received instruction from the fourth official that time was up and blew his whistle.
The decision left the Wales players bemused and frustrated, and coach Gareth Jenkins said White had got it wrong.
"A mistake has been made here and we could have come away with a result if we had been clear on the situation," said Jenkins at the end of the game.
The International Rugby Board law book would appear to back up Jenkins' claim, as Law 5.7 (e) states:
If time expires and the ball is not dead, or an awarded scrum or lineout has not been completed the referee allows play to continue until the next time that the ball becomes dead...
However, television replays suggest that time had expired by the time Hook kicked into touch, so the fourth official told White to end the game with the ball dead.
Italy scrum-half Alessandro Troncon had no sympathy for the Wales players, blaming them for taking too long to take the penalty.
"Wales had 10 seconds left to play but the referee was correct because the Welsh players were talking about what to do and they took their time," he said after Italy's historic 23-20 victory.
"Fortunately for us the official correctly decided to blow the final whistle."