Cullen: It's a physical game
Leinster 22 Exeter 17
Circumstances arise alright.
Minute one. Mat Kvesic's head accidentally separates Jonathan Sexton from his senses and second row Sam Skinner powers past Garry Ringrose for Gareth Steenson to convert.
Minute two. Sexton is accompanied from the field for a Head Injury Assessment from which the out-half would not return.
Minute six. Replacement Ross Byrne's jaw cracks against the point of Nic White's shoulder, as both men dip into contact, and Byrne leaves for a Head Injury Assessment before returning.
Minute seventeen. Cian Healy drives his shoulder into Luke Cowan-Dickie's head for a yellow card which could have been red.
Minute 28. Leinster's seven-man scrum is pummelled for Stenson to m ake it 10-3.
Minute 30. Exeter's maul blows Leinster back for hooker Cowan-Dickie to claim their second converted try for a 17-3 lead and Scott Fardy is very harshly binned for his part in pulling it down.
The manner in which Leinster coped with adversity suggests however far they go in the Champions Cup this season, the will not fall short for lack of character.
They spent half of the first half with fourteen men and Isa Nacewa's second and third penalties were taken while Fardy was in the bin.
Further, Exeter would not score for the last 50 minutes of the game as Leinster turned the tide.
Minute 66. Leinster take the lead for the first and final time when Dan Leavy creates a try for Luke McGrath.
Coach Leo Cullen was bothered by mixed emotions, the frustration at getting into a big hole, the admiration at getting out of it.
He was even more bothered by the primary post-match focus on concussive-ty pe blows to Jonathan Sexton, who failed his HIA, Ross Byrne, who passed his HIA, and Sean Cronin, who didn't have a HIA but lost a tooth for his trouble.
"You are obviously digging for something. I don't know where we're going here," said Cullen four times.
Breaking down each incident, Sexton has been using the same tackle technique for years.
He targets man and ball in a Rugby League-style upright fashion, making contact to the head more likely.
His replacement Byrne, not known for his aggression in the tackle, looked like he was keen to challenge this perception in catching White's shoulder.
Cronin has always had his tackle technique as a work-on, seeing yellow for a high tackle in Sandy Park the week before.
On this occasion, the hooker was upright and upended due to getting into a bad position.
The Leinster medical staff were on the scene in seconds and used their expertise to assess the three situations.
In addition, Hawkeye is in place so that further medical examination can be carried out on all relevant incidents. Two out of three were removed and one was not allowed back on.
While player welfare is quite rightly a sensitive issue in the game, every contact to the head is a cause for concern, not necessarily a cause for a HIA.
There is a world of difference between a tackle in which a forearm or shoulder is used with force to the head and one where head meets head or shoulder.
"There is more and more protection for players than there ever has been in the past. The game is a hell of a lot cleaner," said Cullen.
"If you look back at the history of the game, people just got up and played on.
"That doesn't happen anymore and rightly so, because player safety is paramount."
It was then Cullen found his feet in the discussion.
"Why are people attracted to the game? Because it is a physical game," he said.
"That is the amazing thing about the game. It is an amazing sport when guys are willing to sacrifice themselves like that.
"When I was a kid playing rugby for the first time, what did I enjoy about rugby? Going around tackling people."
By the way, Leinster have won their first four matches in Europe for the first time in twelve seasons to lead Pool 3.