He wasn't being very careful when he made a throat-slashing gesture after a fight during a preseason game, ignoring an NHL video that illustrated behavior -- including the throat slash -- that would not be tolerated. The result was a one-game suspension to start the season.
And Boynton hasn't been very careful the last two games as he sacrificed his body to block 10 shots. He currently leads the NHL with 26 blocked shots in seven games.
But in fact, Boynton, 31, is an extremely careful athlete. He has to be, because he's been a diabetic since he was 20.
"I test my blood sugar about 8-10 times a game," Boynton said. "I do it on the bench sometimes, but mostly in the intermissions. I'll throw my insulin pump back on and adjust accordingly.
"I have a handle on it. Every day is different, and it affects things a little bit. It affects the way you feel. You can get pretty messed up."
His teammates have noticed his dedication to staying on top of his condition.
"The diabetes is something he has to live with, but he does a good job doing it and keeps himself healthy for the game," Brent Seabrook said.
Since coming over in a minor deal from the Anaheim Ducks for future considerations before the deadline last season, Boynton has made an impact on and off the ice.
"He's a great guy," Seabrook said. "He's an awesome teammate and has become a good friend."
To be accepted by the defending Stanley Cup champs reflects how far Boynton has come from his days in Anaheim, which he left with some bitter feelings.
"I played for a coach in Anaheim that told me I wasn't good enough to play in the NHL," Boynton said. "I wasn't given an opportunity to do anything there, so when somebody feels like that about you and they are not going to change their mind no matter what you do, it's tough."
Boynton is referring to Ducks head coach Randy Carlisle, who declined comment through a Ducks spokesperson. Carlisle eventually banished Boynton to the minors last season for the first time since 2000.
Boynton's confidence dropped, but the trade and an appearance in the Stanley Cup finals brought Boynton back to life.
"Confidence is a funny thing," Boynton said. "Sometimes you have it, sometimes you don't. I was just fortunate to get out of [Anahiem]."
Boynton is making the most of his opportunity, and part of his success is being careful, at least off the ice.
"It's a lot better to check [his blood] than to pass out," Boynton said. "It's like having coffee in the morning. I've been doing it for so long it's like second nature."