You are mistaken, Martin. The CO of that DDG is the local anti air warfare commander. He's got the better Aegis system than we had on our cruiser (20+ years ago) but the role is the same. When you are the local Air Defense commander, every single air contact is tracked and of interest until you are certain that it is on a opening course and speed relative to the battle group you are protecting. IF this contact was being tracked (not sure if the ship was in a position to do so the evening it went missing) then its track would have been identified and tracked by the guys on the scopes in Tracker Alley in Combat Information Center. I've stood enough watches in CIC in an AAW command ship to know how this works. (Yes, it's been a few years!)
Thanks for the clarification. Always welcome to get a better understanding. :-)