In defense of Rufus Wainwright, a Canadian-American who sang the National Anthem at Dodger Stadium prior to Game 5 of the World Series, mistakes happen.
Wainwright, tasked with singing in front of 40,000+ fans, likely felt pressure, and it seems many American fans didn't notice his clerical error.
A correct performance of the Canadian anthem on baseball's grandest stage is warranted and expected, especially given the current Canada-United States relations.
Wainwright surely knows the words or else he wouldn't have volunteered to sing the song in the first place.
Author's summary: Rufus Wainwright's singing of O Canada had mistakes.