Is that why the disciplinary action was taken? We do not know.
There is absolutely zero-doubt in my mind that is why administrative action was taken. The Houston PD stated to West Point that a cadet had assaulted someone and "smelled" of alcohol. West Point, took a knee-jerk reaction (I am not saying this is necessarily wrong decision) and assumed that he committed the offense. Otherwise, if they were not sure, they would not have acted. Since administrative action is not punitive, it is in no way imposing judicial type of punishment.
The WP PA rep. inferences that the sole reason for action was based on "the inappropriate use of alcohol." I'm presuming (which sometimes can be bad) that if a cadet has had two alcohol incidents (especially one as a 1/C and as grave as the Houston PD reported), then they would be booted (not kept); I could be wrong, though.
I think it is fair to say that the Houston PD did not act with the professionalism that is required of their job, that they did not thoroughly investigate the incident (including neutral witnesses), that Cadet King has a slam dunk case in civil court and that, presuming the limo driver's version of the events are correct, the force was excessive and beyond self-defense. Right now, the only facts of assault that are documented on video/photos, is that of Cadet King being beat-up and not of Cadet King assaulting the limo driver -- and there is a neutral witness who said King didn't do anything wrong.
Who knows if King had more to his conduct record than this alleged incident, but I sure hope that if this is his sole incident (barring minor conduct offenses), that WP corrects the situation pending a change in the police report or civil suit. To not do so, would be hypocritical of the school's "code of honor" that is cited in the report to the Houston Chronicle.
No one also knows how many a "few" drinks are and when they were consumed. No Breathalyzer or BAC was conducted, so based on the neutral witness and the limo driver (the same one who said he fell into the concrete slab), there is no factual basis that can claim if he truly was publicly intoxicated.