The All Blacks have an exemplary record of managing players whom they know have had head knocks.
Their duty of care is world leading and they quite simply don't gamble with a player's well being. Doesn't matter who it is - what the needs of the team are or the score in a game - if they know or suspect a player may be concussed, they take decisive and protective action.
It's necessary to labour this point lest anyone should interpret wrongly the concerns that have arisen in the wake of Saturday's test where video footage from early in the game which appears to show Sonny Bill Williams stumbling awkwardly after a major collision.
Footage can often be deceiving, allude to things that aren't there but in this case, it's better to believe that Williams was staggering because he took a major blow to the head.
And because he was staggering like that, he should have been taken off according to protocol. Taken off as in removed the field and not returned regardless of whether he passed a concussion test or not.
Which begs the question - why that didn't happen? That's what Sanzaar will try to determine in the next few days.
They will review what happened from the moment Williams was involved in the collision through to him continuing to stay on the field for the remainder of the game.
It won't be about apportioning blame, more a case of trying to understand where the process failed. And it did fail somewhere along the way.
Ideally Williams should have said something to the medics. Ideally, one of his teammates should have said something to the medics.
Ideally the independent match doctor should have picked up the incident while monitoring the video.
In the last few years rarely has this first line of defence been breached as it were. Usually between the player, his teammates and the independent doctor, head knocks that need to be investigated have been.
If this group doesn't see something, the hope is that the team doctor or one of the coaching team will see what happened and alert the right people to it to ensure the individual in question is treated appropriately.
But the system isn't perfect as this incident involving Williams would attest. Somehow everyone missed what happened and the reasons why need to be understood to help make sure it doesn't happen again.
Williams has reported back for duty symptom free and passed fit and ready to play. While that's a welcome outcome, it doesn't make the failure of the process right or reduce the need for answers to be sought as to the failure to identify the need for action at the time.