CORTINA D’AMPEZZO, Italy — It was the last end and the U.S. men were down 8-2 against Switzerland on Thursday in their first match of the men’s curling round-robin. In other words, the stakes were low — and the time ripe — for a 54-year old personal injury lawyer and six-time winner of “Minnesota Attorney of the Year” to make Olympic history. The team called a substitution and Rich Ruohonen, from Brooklyn Park, Minnesota, stepped onto the ice. He hurled the corner guard and watched his stone, biting his lip, until it made it safely to the house’s left flank.“Yeah baby! Good shot, Rich!” skip Danny Casper — 30 years younger than Ruohonen — shouted across the ice. U.S. fans gave a standing ovation. The lawyer looked wistful. Ruohonen had just become the oldest person to compete for the U.S. at the Winter Olympics. “I would have rather done it when we were up 8-2 instead of down 8-2,” he said, “but I really appreciate the guys giving me a chance.” Since inviting Ruohonen onto their team as an alternate for Casper, who has Guillain-Barre syndrome, he has become something of …