In the intro, the narrator gives Rabb's rank as Lieutenant Commander when he crashed, and was diagnosed with night blindness, yet throughout the first season his rank was Lieutanant, and he was already in the Judge Advocate General Corps.
Every scene begins with a graphic which depicts the time in military format and the word "Zulu". Zulu is the military phonetic designation for the time zone known as Greenwich Mean Time (GMT) or Coordinated Universal Time (UTC). In most cases, the time listed corresponds to the apparent local time rather than ZULU time. For instance, the start of the workday in Norfolk Virginia would more likely be 0700 Eastern Standard (Romeo) Time or 0700 Eastern Daylight (Quebec) Time and certainly not 0700 Zulu, which would correspond to a local time of 0200 or 0300 which would be early even by military standards.
In several episodes, the show's writers confuse the United States Penitentiary at Leavenworth and the United States Disciplinary Barracks at Fort Leavenworth. The USP is a federal prison. The USDB is the military prison. On several occasions pictures of the USP are used to represent the Disciplinary Barracks.
In later seasons of JAG, the introduction shows a brief segment of AH-64 Apache attack helicopters flying in formation. However, as the opening credits are intended to display Navy and Marine Corps activities, this would be a bit out of place, as neither the Navy nor the Marine Corps operates the AH-64 - in the US Military, only the Army does, while the Marine Corps employs the AH-1W 'Whiskey' Cobra.
Throughout the series ships' crews wore their covers, whether they be ball caps or dress covers, while aboard ship. Navy regulations require covers to be removed by all personnel while inside a ship or a building. On a carrier when out at sea, indoors or out, covers are removed. If a cover flew off on the flight deck it could damage the engine of an aircraft.
Throughout the series, when aboard ship, the baseball caps have a silhouette of the ship. The actual caps have only a blank space between the ship's name and hull number. This space is filled with a pin designating the person's rate/rank.