Mendez was known for his on-the-scene management of the "Canadian Caper" during the Iran hostage crisis. He helped rescue six American diplomats from Iran in January 1980 by arranging to have them pose as a Canadian movie crew. As part of their cover, the diplomats carried passports issued by the Canadian government to document them as Canadian citizens. This was loosely made into the 2012 Academy Award-winning movie "Argo".