According to John Branch's fine December 2011 series on Boogaard's life and tragically early death in the New York Times, more than 20 dead former NFL players have been diagnosed with CTE. In the five months it took to examine Boogaard's brain, two more NHL enforcers died, allegedly from suicides.
As a result of such studies the NFL has moved to outlaw helmet to helmet contact, while ice hockey continues to wring its hands over the place of what is sanctioned fighting in the game.
It is to that backdrop that the NRL is attempting to deal with the issue of incidental head contact in league. Bulldogs and Kiwis forward Frank Pritchard being suspended for a week for a tackle not dissimilar to Kidwell's was the first sign of a crackdown, while this week the NRL reportedly issued "please explain" notices to two clubs after players were allowed to remain on the field after being knocked out.
Raiders centre Shaun Berrigan was allowed to play on after suffering a head knock in his side's win over the Titans, while Dragons player Nathan Green was allowed to continue without leaving the field despite play having been held up for several minutes while he was down.
"The NRL is closely monitoring the compliance by clubs with the league's concussion policy," Nathan McQuirk told Sydney's Daily Telegraph newspaper. "We've requested reports from two clubs following last weekend in relation to possible head injuries sustained by players. These reports and video will be reviewed by the NRL chief medical officer."
New concussion guidelines state players who have received severe head knocks must undergo cognitive tests if they are to stay on the field. If they fail, they are then assessed by their club doctor on the sideline.
All well and good. However many involved in the game, such as former Kiwis fullback Richie Barnett, question whether much is really being done about the issue. In a sport where big men repeatedly clash with much smaller opponents, eliminating head knocks was simply not possible, Barnett wrote in yesterday's Herald. He also questioned whether there was really much desire on the part of clubs and players to force through change.
Vatuvei's escaping any sanction for his hit on Tonga appears to be a classic case in point.
"I never intended to go that high," Vatuvei said. "I just went in for the tackle and he kind of slipped. I tried to apologise to him and I stayed there to see if he was all right. Tackles around the head are really serious and can cause a lot of damage. I'm really against high tackles but sometimes they are accidents."
The NRL's match review committee clearly felt the same way, however its ruling incensed the Bulldogs, with the club complaining of a lack of consistency.
"It's fair to say we are all bewildered with the inconsistency of the current system," Bulldogs chief executive Todd Greenberg said.
"We are not questioning the integrity of the other clubs or the players; but we are simply questioning the inconsistency of the system.
"We are obviously conscious of our obligations to comply with the rules of the game, but we are also mindful that rugby league is a contact sport and sometimes accidents will happen.
"But after dealing with the events of last week we now watch similar tackles from games over the weekend and are left confused and frustrated. We accepted last week's ruling based on an understanding that the same principles would be applied consistently throughout the season."
Greenberg's assertion the club accepted the NRL's ruling is a bit rich. Rather than accepting any culpability on Pritchard's part for a tackle that left Penrith winger David Simmons concussed and out of action indefinitely, the Bulldogs defended the charge at the judiciary, arguing forcefully that Pritchard had done nothing wrong.
"We were told last week that Frank Pritchard's tackle was deemed a careless grade one offence," Bulldogs coach Des Hasler said. "We were told that the burden of care was placed on him when tackling. We were told that an attacking player who stepped late or was falling was no excuse and that the burden was on the player to bend his back to ensure no contact was made to the head of an opposing player.
"We were told that any contact with another player's head can be deemed a careless high tackle."
Clearly the line has been redrawn. Running as it does between accidental and careless, it is an extremely fine one.
In clearing Vatuvei, the match review committee found "there was some contact between Vatuvei's bicep/arm and the head of Tonga as a result of Tonga slipping into a tackle. The contact was deemed to be accidental and not careless. A penalty was deemed to be sufficient."
Warriors coach Brian McClennan was in no doubt that Vatuvei's actions were accidental, but couldn't offer a definitive answer on what should be done about incidental head contact.
" It's a hard one," McClennan said. "It is always about the intent. You could clearly see in Manu's particular case there was no intent there at all. In fact he just stayed with Tonga to make sure he was okay. When guys are flying out with the intent of really trying to hurt somebody and they hit the head, that has got to be looked at."
For his part, Vatuvei believes the current rules do adequately protect players: "For sure. The rules at the moment are pretty good. Any contact with the head has got to be serious. It can cause a lot of damage."
Which brings us back to Pritchard and Simmons. While the Bulldogs were incensed by Pritchard's penalty, he will be back in action tomorrow at Mt Smart Stadium. So too will Vatuvei. For Simmons, whose concussion symptoms have yet to clear, his initial sentence looks like being at least two weeks out of action. Long-term, who knows?
