With six stitches and some skin adhesive holding the bridge of his nose together, O'Brien pondered the irony that as a victim, his blood splattered across the ice in a second-period collision with Dustin Byfuglien's stick, he may have felt better than he did from the other side.
"I wouldn't say better," O'Brien said with a laugh, "but it feels good right now."
It was a winner's laugh after the Canucks defeated the Chicago Blackhawks at the United Center 4-1 to stave off elimination and force Game 6 of the Western Conference semifinals back in Vancouver on Tuesday night.
The Canucks may be stubborn, but stupid they are not.
After three consecutive losses, the last two in large part because they had begun taking their mail in the penalty box, they figured out that 5-on-4 hockey was just not working for them.
And so, go figure, the Canucks raised their level of play by dialing it down a notch.
After giving up a combined 14 power-play opportunities in Games 3 and 4 resulting in six goals and, not coincidentally, two losses to the Blackhawks, Vancouver committed just four penalties in Game 5 and killed both in a decidedly more disciplined overall effort.
O'Brien said he took it as a personal challenge.
"Before the game, I'm usually pretty talkative, trying to get the boys going, but today I just tried to stay focused, take some deep breaths and calm down," he said. "You have to control your emotions this time of year, and we learned that the hard way in Game 3 and 4."
O'Brien was one of several Canucks to turn Byfuglien into a tackling dummy in Game 4, making two trips to the box in the first period, and O'Brien was apparently not going that road again.
"I was just trying to give Big Buff a hard time, but it ended up costing us," he said. "But you make mistakes, you learn from it; that's what life is all about."
The Canucks converted 1-of-6 power play opportunities in Game 5 while Vancouver goalie Roberto Luongo had 29 saves and allowed no rebounds to control the majority of action from faceoff.
"A lot of [our penalties] were stick infractions," said Hawks defenseman Brian Campbell. "It's not like we got mad and slashed somebody. We just weren't sharp. ... We didn't play our best game, didn't come close to finding ways to win tonight. Tonight we definitely didn't have it."
Naturally it begs the question why. Why have two teams that dominated on home ice this season failed to take advantage in this series? The Hawks are now 3-3 at home in the postseason.
"I don't have an answer," said Hawks center John Madden. "I know, speaking for myself, I don't go into the game thinking we're better at home."
Weirder is the fact that the visiting team in this series has scored first in each game; the Canucks took a 1-0 lead just 59 seconds into Sunday night's game on a long slap shot by Christian Ehrhoff, then made it 2-0 later in the period on an 8-foot wrister by Kevin Bieksa.
Coming into the game, the Canucks had actually outscored the Hawks 9-8 when playing at even strength. Faced with that scenario Sunday, the Hawks reverted back to the seemingly slower, defensive team they were in Game 1 of the series.
"We were looking for pretty plays instead of simplicity," Hawks coach Joel Quenneville said.
The Canucks' plan couldn't have been simpler -- keep the Hawks out of the middle and force them to score from the outside -- and they made the execution look easy, as well, with the Hawks' shots sailing wide and high. Limiting time and space, as they call it.
"You're trying to shoot over guys and through guys, and you're putting a little more on it than you're used to," Madden said.
The Hawks have played their best this postseason after looking their worst, and are darn near unstoppable when the situation is desperate, which means they should be better in Game 6 and, if necessary, in Game 7, which would be back in Chicago on Thursday.
Not that the Hawks were buying that.
"Tonight we looked at it like [a Game 7]," Campbell said. "We knew how important it was."
If the Canucks take this new calm-and-cool approach back home, the San Jose Sharks may get even more rest than they bargained for.
"We just have to take the same attitude and not get too excited," O'Brien said. "I guess the word in this series is 'composure,' and I guess I'm going to jump on board with it. We just have to play composed."
Melissa Isaacson is a columnist for ESPNChicago.com.