The Calderon family had more excuses than someone trying to get out of a speeding ticket. Their main argument for staying in Japan was to remain with their daughter, who they claimed only speaks Japanese. That story is very hard to believe, but if it is true they are really naive parents who were living in a dream.
Consider this scenario: A Japanese family is sent to the United States on business and they know they will return to Japan in the future. Every day the parents and children have to speak English. So at night, when the family members are at home and want to relax, they revert back to their native language, Japanese (keep in mind that all good Japanese parents send their kids to Japanese classes when abroad). It's just common sense, and all of my Japanese friends who followed the "Calderon plot to stay in Japan" (and originally felt sorry for them) agreed with me.