To Russia with Love (1) - S3-E24
Character mistake: While talking with Falcon, Harm mentions the "green book" Falcon stole that listed all of the American POWs transferred to Russia after the Vietnam War. But when Harm originally found the book in "Ghost Ship", its cover was yellow.
Adrift (1) - S6-E24
Character mistake: When asking Skates if she saw Rabb eject, she is referred to as Commander when her rank is Lieutenant. (00:40:10)
Fair Winds and Following Seas - S10-E22
Character mistake: Characters occasionally refer to Rabb as "Commander", even though they know he was promoted to Captain.
Character mistake: When Harm is questioning agent Novack about whether there was an "angry demeanor" amongst the Marines on the day of the shooting, Mac objects that he is "leading the witness." However, Novack was her witness to begin with, and Harm was cross-examining her. Leading questions are permitted during cross-examination; as an experienced trial lawyer, Mac should know this.
Answer: Officially, the individual has been ordered to attend, failing to could be interpreted as either, Failure to follow orders, dereliction of duty, going AWOL, or even desertion. It would depend on the underlying reason as to why the person doesn't appear.