Rape? Assault and battery? Adultery? Conduct unbecoming and Officer or NCO?
Any of these charges can be brought forth under the UCMJ. This is always appropriate when conduct warrants it and is taught to all members of the Armed Services. What's your point? Any illicit behavior can be disciplined at any time in the military, but what has been described in this "blowing off steam" episode doesn't appear to have crossed into that territory.
This cold water comment is as valid as a soldier coming forward and claiming "murder." Throw in any criminal conduct and you've changed the facts of the case. I have not heard of any charges of rape or murder being leveled in this matter, so your point is moot.
This "blowing off steam" party went too far IMHO.