Warning Signs.

So, this kid has jeapordized his future with the Marine Corps simply because he wrote an essay that states: "“Blood, sex and booze. Drugs, drugs, drugs are fun. Stab, stab, stab, stab, stab, s...t...a...b...puke. So I had this dream last night where I went into a building, pulled out two P90s and started shooting everyone, then had sex with the dead bodies. Well, not really, but it would be funny if I did.”
His lawyer states: “There was never any warning from the teacher that if she determined the paper to be offensive, she would then pass it along to the authorities.”

First of all... isn't that warning implied? Do our teachers really need to footnote every assignment with a statement indicating that the authorities will be notified if the student's actions are not in line with appropriate safety measures?
Second of all... if no one had been notified and this kid had come to school with "...two p90s and started shotting everyone..." wouldn't we be kicking ourselves for ignoring the warning signs?
Third... do we really want someone in the Marine Corps if he's made it to April of his Senior Year of high school and still hasn't learned that this may not be the most appropriate way to express himself on a creative writing assignment?