It was a spur-of-the-moment decision by an underdog snowboarder, overshadowed on his own team by superstar Shaun White, who had pulled out of the slopestyle competition earlier this week.
As Kotsenburg, who earned his spot in the finals by placing second in the semifinals earlier Saturday, prepared for his run, he called his older brother, Blaze, who was at home in Park City, and U.S. coach Bill Enos to share a crazy idea.
He wanted to throw a trick called "Back 16 Japan" on his first run in the Olympic finals, never mind that he hadn't tried the move in practice or prior competition. No one talked him out of it.
"I ended up landing it, and winning with it," Kotsenburg said, laughing. The trick is four and a half backwards spins (1620 degrees of rotation), while grabbing the backside of his board (Japan).
Kotsenburg, the third rider in the 12-man final, received a score of 93.50 on that first run, and that score held up through the nine competitors that followed him, and through all of the second run.
Canadian Mark McMorris cleanly landed a pair of triples in his second run and received a score of 88.75, stunning both McMorris and the large Canadian contingent who had traveled to Rosa Khutor to watch him and his two countryman. Norway's Staale Sandbech, the second-to-last competitor, knocked Morris from silver to bronze with a score of 91.75.
"I would have loved to be in the gold medal position, but to have been through what I've been through the last two weeks, to be standing on the podium in general feels like a gold medal to me," said McMorris, who suffered a broken rib at the X Games last month and failed to earn one of the automatic spots in the final out of qualifying Thursday. "I wanted to go big, land clean, hit technical tricks and, yeah, you've got to be happy with how you rode, and it's up to them to make the decisions."
Thus controversy will mark slopestyle's debut at the Games.
McMorris said he believed when he finished his second run that he should have scored in the 90s, and that he had given a performance that should have been good enough for gold or silver.
It wasn't a slight at Kotsenburg, whom McMorris and other Canadians praised, but an indictment of what riders say is a confusing judging process.
"I just don't know what the judges wanted to see on the course today," said Canadian Max Parrot, who finished fifth with a score of 87.25.
Kotsenburg did not attempt a triple jump, and won with a run that emphasized creativity, style and a technical combination of spins and grabs, including his own creation named the Holy Crail, which he used twice in his winning run.
"It's pretty sick to see that some weird, creative stuff got rewarded," Kotsenburg said.
Indeed the judges and competitors alike seemed to notice and appreciate his array of unique moves.
"He got his own personal style, and I'm happy that he showed that to the whole world. I think his style is pretty rad," Parrot said.
Kotsenburg was the only American in the final, after two teammates failed to advance out of Saturday's semifinal, and White withdrew 48 hours before qualifying began. White, who will compete in the halfpipe next week, didn't have a triple jump in his arsenal of slopestyle tricks, but Kotsenburg didn't need one to win.
And now snowboarding has a new American star – a 20-year-old Utahan with scruffy long hair and a vocabulary full of snowboarding lingo.
Mike Jankowski, the U.S. team's head coach for halfpipe and slopestyle, said Kotsenburg is the purest type of snowboarder, who approaches every run in practice and competition as a chance to have fun and be creative.
Together they ate a small lunch between the semifinals and finals, concluding the meal by deciding to "go snowboarding." It's the type of conversation they could have had on any mountain on any day – it just happened to be on the biggest stage in slopestyle history.
"He's the best ambassador you could have for snowboarding right now," Jankowski said. "He's showing the true love of the sport.