Campbell Robertson reports for the NYT,  "A Louisiana sheriff has apologized for the arrests of as many as a dozen or more men in recent years on charges that they violated an anti-sodomy statute that has been ruled unconstitutional by the United States Supreme Court."  That was Lawrence v. Texas (2003).

But ignorance of Supreme Court precedents is not limited to small-city sheriffs.  U.S. District Judge Claudia Wilken of Oakland, California, said while ruling on a Batson motion, "I don't know that, number one, Batson applies in civil."  Yes, it does.  See Edmonson v. Leesville Concrete (1991), a precedent twice as old as Lawrence.  Judge Wilken said she also did not know if Batson applied to sexual orientation, which is indeed an open question. Adam Liptak has this story in the NYT.