Halcon's henchmen call Sherlock "Chele" when they bring him for questioning. "Chele" means "fair-haired" or "blond/blonde" in Spanish slang. This was a fitting nickname, as the name "Sherlock" is also Old English for "fair-haired" (blond/blonde).
This episode marks the first time Joan Watson (portrayed by Lucy Liu) speaks Mandarin, when she relates the Chinese idiom "Wan Bi Gui Zhao" which she then translates to "return the jade intact to the state of Zhao". Lucy Liu actually grew up speaking Mandarin and did not learn English until she was 5 years old. Despite her fluency in her native tongue, Elementary often has Sherlock - not Watson - speak Mandarin when necessary, though she will often respond in English to spoken Mandarin or translate it into English without saying its Mandarin counterpart. It is not known why Elementary doesn't use Joan's knowledge of Mandarin more often, especially in episodes that feature its use.
Jon Huertas, who plays Halcon, plays detective Javier Esposito in another police procedure drama, Castle (2009).