The Highlanders say they followed the correct protocol in letting prop Josh Hohneck back on the field last Saturday night, despite him appearing to be knocked out.
But the wash-up from the incident has led to New Zealand Rugby making television footage available to the match-day doctor to check possible concussions.
Hohneck clashed with Crusaders forward Jordan Taufua early in the match and was taken off by Highlanders medical staff.
Highlanders doctor Greg Macleod and physiotherapist Adam Letts helped Hohneck, and the prop left the field. He came back on after passing the concussion test sideline.
Under World Rugby protocols, players suspected of being knocked unconscious, or who are clearly dazed, must be removed from the field immediately and are ineligible to return to the match.
Highlanders general manager Roger Clark said the doctor took Hohneck to the sideline and gave him the concussion test which he passed, and was allowed back on.
''We then checked him after the game and he passed and we have tested him since and he has passed. Every rule was followed and the doctor followed every protocol,'' he said.
''There is no way our doctor would have sent him back on if he had not passed the test and was showing the symptoms. Our doctor is not that sort of guy to do that.
''The coaches are not going to push him back on. We're all here for the long haul. We have got a long season and the player's welfare is the most important thing.''
Clark said franchise doctors are employed by New Zealand Rugby and answerable to that organisation, not the coach.
''The doctors have meetings every week and if you started letting people back on when they shouldn't they would be soon told about it.''
Concussion is not clear-cut like other injuries. Some players can get concussed more easily than others.
Some can receive big hits to the head but not be concussed.
The Highlanders take concussion very seriously, Clark said.
Wider training squad member Lee Allan is not allowed to play and train at the moment as he had not passed a concussion test.
A date for a return to the field for loose forward Allan is unclear.
New Zealand Rugby's general manager of rugby Neil Sorensen said yesterday ensuring medical staff saw the same pictures as viewers and spectators was crucial.
To that end there would be a trial in Saturday's match in Wellington between the Hurricanes and Waratahs where the match-day doctor would get that same vision.
''It's really important for the players and game's sake that whatever footage we can get needs to be given really quickly to the right people,'' he said.
''The match doctor on the sideline, who might be very busy assisting the team doctors with an injured player - these guys and ladies need to have footage as soon as possible to make accurate decisions and determine if there has been a suspected concussion or a head knock for them to say that player should be off.
''We believe the key thing is to give everyone the right tools and then educate everyone including players themselves and the coaches that taking a head knock is not worth winning a game or winning a championship.''
Sorensen said he would be reluctant to give the television match official extra responsibilities in terms of watching for potential concussion injuries, preferring to leave it in the hands of medical professionals.
