John (Ambie) McMahon played in seven games for the basketball team in his third year of law school, which its yearbook noted was his third law school in as many years. "We are of the opinion that his nickname is a contraction of "ambulatory," the yearbook noted.

Further information on McMahon's legal career after Georgetown remains unknown, although his son, John Jr. (1927-2009) lived in the Westfield area.