He is not lying and I don't think this a wise area to attack him. Appointments to the Naval Academy are well respected and difficult to obtain (at least if your dad is not Jon Huntsman). While they have not deployed or technically "served," Naval Academy midshipmen are considered on active duty (while NROTC are considered reserve). Midshipmen wear the uniform and it is understood that they have every intention to serve after the completion of their training/degree. I attended the Naval Academy and it is a 24/7 job and you are held accountable to Midshipmen Regulations, the UCMJ, and are expected to conduct themselves as Officers in Training at all times. You are also sworn in at the beginning on Induction Day, at the beginning of your freshmen (Plebe) year which is the standard for "service". The midshipmen appointment oath is slightly different but applies until you are Commissioned upon graduation where you take the standard Oath of Office for officers.
OATH OF OFFICE
Having been appointed a Midshipman in the United States Navy,
do you solemnly swear (or affirm) that you will support and defend
the Constitution of the United States against all enemies, foreign and
domestic; that you will bear true faith and allegiance to the same;
that you take this obligation freely, without any mental reservation or
purpose of evasion; and that you will well and faithfully discharge the
duties of the office on which you are about to enter, so help you God?
Classes and activities such as lectures, drill, and even attending football games are mandatory and considered a military obligation. They are granted liberty and leave. In addition to academic classes, there are a large number of physical education and officer development course, and the summers are spent training with different warfare communities in the fleet.
You are not obligated to serve in the fleet until you sign your "2 for 7" papers at the beginning of your Junior year, upon which you owe the Navy years of service depending on your selected warfare community (5 years for Marines and Surface Warfare, more for pilots, NFOs because of the extra expense and time they require for training) Up to signing the papers at the beginning of your Junior, you can separate with no financial penalties. The attrition rate for my class was pretty standard, starting with 1268 midshipmen and graduating with ~990. Most of those that dropout do so in the first two years before signing the papers. After that, some still drop out due to violations of the UCMJ, conduct offenses, academic performance, or failure to pass physical standards and supposedly owe the Navy several hundred thousand dollars.