The prosecuting attorney called herself an "Assistant District Attorney." Virginia never has had "District Attorneys." They are called a Commonwealth's Attorney, since Virginia is a Commonwealth.
In the chat room Smitty tells Gibbs that he "makes deposits to" a life-insurance policy. However, in the real world one does not "make deposits" to insurance policies; instead one pays premiums on policies to keep them in force.
While investigating the missing petty officer's house, Gibbs and DiNozzo make reference to the "baseball bat" in the kitchen. The bat shown is, in fact, a softball bat.
When Gibbs photographs Jerry's TV stand, the brief shot of the photo reveals an upside-down Xbox 360 console. It would be impossible to load game CDs into the console this way.