With the Swiss lying one and holding the hammer, Koe attempted a draw on his final shot. But he came up way too heavy, missing everything and putting the yellow Canadian rock through the house.
That mistake left Swiss skip Benoit Schwarz with a decision: play it safe and go for three, or take a risk to go for the unfathomable four-point lead against the stronger squad.
Schwarz chose the latter — and his decision paid off. He came in soft, finessing his final rock for a knockout of the final Canadian stone.
The Canadians could never overcome the four-point deficit.
"We played good. Guys played great. I just screwed up one shot and it was a big one obviously. Four is tough to come back against anyone," Koe told CBC's Colleen Jones after the game.
Canada and Switzerland now sit tied for second after six draws at 4-2, behind 5-0 Sweden, which defeated Canada 5-2 on Friday. Canada next plays the U.S. (2-3).
Forced to chase, Koe, Marc Kennedy, Brent Laing and Ben Hebert clawed their way back, scoring two points in the second and fifth as well as singles in the third and sixth to trail 7-6 after eight ends.
In the ninth end, Canada was in position to for a steal of three, but Schwarz made a clutch shot and scored one to restore the two-point lead.
"I made it just about too good. If that red one doesn't kick out as far for him to come off he's got a tougher shot, but what're you gonna do? We made him shoot against three he had to make a good shot," said Koe.
Kennedy chose to overlook the bungled first end, instead focusing on the other nine to glean some positives from the draw.
"It's a long week. Its easy to give up after you give up that four and we actually didn't play that bad an end. Just the one shot. So I actually thought we played pretty well," said team third Marc Kennedy.
Meanwhile, Koe was more concerned about the tournament as a whole. The Canadians are still 4-2, in good position to make the medal round. And once you're there, nothing from the round robin matters.
"Any time you lose its not fun. Does it matter really where we finish? I don't think so. We just gotta begin the playoffs and we gotta play well regardless of who we're playing," said Koe. "And we feel like if we play well we can beat anyone."