If one has to say “This is a joke”, it seems to amount to: “Just kidding (not kidding).”
This guy is an officer. Is he sharing his sense of humor, daily, with his peers and the 10-20 men under his command? This is the type of infestation that has to be taken out at the root.
The military isn’t like a private business. They have to follow a procedure to protect the individual. Don’t worry, his career is over. He’ll have to spend the rest of his life explaining why he was booted by the military. This is even worse because he is an officer.