The first "factual mistake" is, in itself, mistaken. Actually, "011" at the start of a number is the USA code to access international numbers (the European and British equivalent is "00"). Using the example given in this "goof", to dial a number in Belgium, an American would start by dialling "01132"; For the UK "01144"; and for Russia "0117".
The NCIS and JAG personnel do not wear any form of identification in their intelligence headquarters and the JAG HQ. Especially in an intelligence agency like NCIS, staff and visitors must wear ID tags.
When Gibbs is interviewing Rabb in the interrogation room he turns his cell phone around and asks Harm if he recognized the phone number displayed on the screen, beginning with the country code 011. He then tells Rabb that it's his brother's cell phone number in Moscow. Country code 011 is Belgium, not Russia.