Nixon questions and Howard Cosell questions I get and Nixon Watergate questions were completely fair game in the Zeitgeist. I just never liked it when Patty Deutsch gave answers attacking Nixon family members which came off as totally mean-spirited no matter what your political beliefs. Bash Nixon, but leave his family which suffered a great deal alone.
One of the most obscure topical events I remember coming up on Match Game happened in 76 when there was at least one question in the period when Evel Knievel got into trouble with the law for assaulting someone with a baseball bat (and thus the Evel Knievel question was designed for the answer "baseball bat". The contestant needless to say didn't get it)