Complex sentence: Both the 2010 and 2014 games between the two nations were reffed by Canadians, which some Americans have cited as controversial, even though Canada has a long history of victory under diverse circumstances.
Split into simpler sentences: Both the 2010 and 2014 games between the two nations were reffed by Canadians. Some Americans have cited this as controversial, disregarding Canada's long history of victory under diverse circumstances.