I agree with SASless on this occasion!
From the limited facts reported of the case, I am quite clear that a mutiny charge would NOT have been appropriate. "Mutiny" and "Disobedience of a lawful command" are both very serious offences, but you diminish the seriousness of the mutiny charge by using it where the lesser is applicable.
From recollection, the maximum prison sentences under the respective charges are Life, and 10 years, so the court martial was not constrained in its sentencing options.
The Manual of Service Law says that
Mutiny is the most serious of all forms of indiscipline, therefore, charges under this section should normally only be preferred when the facts disclose a concerted and deliberate challenge to authority which strikes at the very heart of discipline and is calculated to prejudice significantly the ability of a unit to carry out its role, task or duties.
As an aside, I am surprised at the enthusiasm of some posters for talking up one side or the other of what was indeed a serious and embarrassing episode, but hardly a unique event in history.