World Rugby has exonerated Wales for failing to notice George North lost consciousness on the field and allowing the winger to play out the Six Nations loss to England.
Rugby's governing body launched a review of North's medical treatment after watching replays on Saturday, a day after the match in Cardiff. He accidentally banged heads with team-mate Richard Hibbard in a tackle in the 62nd minute, and slumped to the ground unconscious.
North should not have stayed on the field, World Rugby said in a statement on Tuesday, but believed the Wales medical team did not see how the accident happened before attending to him.
"World Rugby accepts the WRU's explanation that neither the team medical staff nor the independent doctor had sight of the incident, and understands that the medics acted within the framework of information they had at the time, and would have taken a different course of action had they had direct pitch-side visibility or access to the same broadcast footage seen by those watching on television," the statement said.
On Monday, Wales medical officer Prav Mathema said team doctors did not see the second-half incident involving North, and that he was lucid when they arrived to treat him.
Having seen video replays, Mathema accepted North should have been taken off.
Mathema added that for the rest of the Six Nations, his medical team will have access to instant video replay.