The recent reviews into concussion management have "thrown the system into chaos", a leading expert says.
"These faultless and blameless reports simply don't stand up," Dr Willie Stewart told the BBC.
"They begin to look like a review process more intent on preserving the welfare of the Head Injury Assessment [HIA] than the welfare of the players."
In the Ioane case, two independent medical reviewers questioned why the player had not been taken off for an HIA.
However, the RFU and Premiership Rugby investigation accepted that the Sale doctor had used his clinical judgment to not remove Ioane from the field of play.
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"The Untoward Incident Reviews around HIA incidents thus far throw the system into chaos and, if they are to be believed, ask serious questions over the HIA and its suitability for the game," Dr Stewart, a neuropathologist who has worked with World Rugby and the Scottish Rugby Union, added.
"In each incident thus far the message seems to be 'the process is flawless, no mistakes were made and no change or sanction is needed'.
"This cannot all be true. That each case is an 'incident' must by definition either raise an issue over process or application."
The RFU says the introduction of the HIA has seen a considerable improvement in player welfare, but Dr Stewart feels the recent judgments have set the handling of head injuries back by years.
"In this latest [Ioane case] both independent medics are reported to have been overruled by the team doctor and their clinical judgment.
"In essence, this would appear to be sanctioning a return to 'on the run' assessment World Rugby claimed was ineffective, hence the reason for the HIA.'"
And Stewart has called for the world governing body to intervene if they are to retain their authority over concussion management.
"There can be no question that an urgent and independent review asking serious questions of the untoward incident review process is required if the HIA and World Rugby are to retain any credibility."