Sale Sharks have avoided punishment over allowing TJ Ioane to continue playing despite suffering a potential head injury in the Aviva Premiership loss at Harlequins on January 7.
Ioane suffered a potential head problem in the 30th minute of Sale's 29-26 league defeat at the Stoop, but was not withdrawn from the contest.
A joint Rugby Football Union (RFU) and Premiership Rugby review panel has ruled the decision not to remove Ioane for a Head Injury Assessment (HIA) was "a matter of clinical judgement by the team doctor".
The Concussion Management Review Group (CMRG) also cleared Northampton of any wrongdoing in December over allowing George North to return to action despite appearing to have been knocked out.
"The group have concluded no further action will be taken and the decision not to undertake an Head Injury Assessment on the player was a matter of clinical judgement by the team doctor," read a joint RFU and Premiership Rugby statement.
"The team doctor's decision was based on his view of the injury mechanism in both real-time and following video review, and his direct assessment of the player's immediate and subsequent response to the injury event.
"The team doctor was in the immediate vicinity of the player, reviewed the real-time video footage and was best placed to make that decision.
"In continuing to monitor, reassess and question the player, both during and after the match, the team doctor was continuing his responsibility to evaluate the player's condition for any signs of a suspected head injury or concussion; none was apparent.
"While a case could have been made for the player's removal for an HIA following the incident, the group felt that the decision for the player to play on and be monitored was consistent with the range of current practice and current interpretation of the criteria for requesting an HIA.
"The decision to instigate the HIA then becomes a clinical judgement call of the doctor at the time."
The ruling to clear Sale is the latest chapter in a troubling time for the north west club, following the sacking of Tom Arscott on January 19.
Sale dismissed Arscott after claiming the winger had leaked sensitive team information to Bristol ahead of the sides' Premiership clash, via his brother Luke.
Bristol went on to beat Sale 24-23 at the AJ Bell Stadium, with Tom Arscott then suspended by the Sharks on January 4.
The concussion panel reviewing the Ioane incident was chaired by Dr Julian Morris, and comprised the RFU's professional rugby director Nigel Melville and Premiership Rugby's rugby director Phil Winstanley.
"The independent medical reviewers, in carrying out their role, were correct to question the medical team's assessment and treatment of the player," said independent chairman Dr Morris.
"The process of review and reinforcement of the HIA protocol must continue to take place.
"In referring this matter to the group, the Independent Medical Reviewer has exampled the positive nature of the process in being able to challenge clinical fellows in the interests of player welfare."