1 - The pilot is called a Lieutenant Commander but his picture on the NCIS screen shows him wearing a saucer cap with "scrambled eggs" on the visor. In the Navy, Marines, Air Force and Coast Guard, an officer doesn't start wearing that type of cap until he reaches "full" commander (in the Navy & CG) or Lieutenant Colonel (Marines or USAF), pay grade O-5. The Army differs in that you switch to the scrambled eggs visor upon reaching Major, pay grade O-4.
2 - When Petty Officer Sparks is in the NCIS interrogation room, her JAG counsel refers to her as "Lieutenant" Sparks. NOT an error that would ever happen.
As a retired military officer, I've always been impressed by NCIS' ability to get the military details right. The first error was somewhat subtle. The second one wasn't.