McMorris, 32, fell in two of his three attempts in the final after recovering from injuries suffered in a training crash. Spalding, the 2024-25 World Cup champion, was unable to secure a medal position despite his strong form this season.
Gold went to Su Yiming of China, with Japan's Taiga Hasegawa taking silver and American Jake Canter earning bronze. New Zealand's Dane Menzies, born in Alberta, finished seventh after being the top qualifier.