I don't know if I would have banned him under the circumstances you describe, but it is also not my call. Further, since I did not see that thread, I don't know if he was banned solely because of the circumstances you describe. Finally, I don't know if the banned poster was a young marine.
The marine was my nephew posting from my computer and it happened as I stated.
I have some experience with banning personal and otherwise and I can tell you there have been some real quick triggers especially under the flag-a-mod system. If you get under the skin of the wrong person on the wrong day, you're toast.