Contrary to what is usually portrayed in the series, this case involves a valid connection to NCIS jurisdiction. In this instance, counterfeit currency being investigated by the US Secret Service has a tie in to the US Navy via suspected corrupt personnel. NCIS would indeed investigate such a case.
This episode was shot during the production of the previous season, hence the absence of Assistant Director Mosely and Hetty's Vietnam storyline. Another indication of this is Deeks's facial hair, which was longer than usual in the season premiere, back to normal in this episode, and returns to its newfound longer length in the next episode.
"Se Murio El Payaso", the episode title, is Spanish for the "The Clown Died".