Dear MindBender26,
A person cannot be hospitalized against his own will if he doesn't meet the two criteria you mention.
But a person can check himself into a mental hospital of his own accord.
I didn't see that the committal you mention was involuntary. If I missed it, I apologize - I'm still only on my second cup of coffee. But if it was voluntary, then it is possible that he wasn't sufficiently disturbed to be categorized as "mentally ill," or a danger to himself or others.
sitetest
For depression, hospitalization often follows significant suicidal ideation and/or a suicide attempt.
Please see #88