Previously thought to be. goof. Gibbs has supposedly never taken a polygraph before Susan administers one. Yet the director tells him that failing it will cost him his NCIS clearance. Left unanswered is how he obtained a polygraph-dependent clearance without ever taking a polygraph. When Gibbs became an NIS agent polygraphs were not necessarily required for even a top level security clearance.
Ducky calls the mite a crustacean, when it is actually an arachnid related to ticks.
When Gibbs is questioning the judge while she's connected to the lie detector, he mentions Skokie County in Illinois. There is not a Skokie county in Illinois. There is a Cook County courthouse located in the city of Skokie.