I commend you on your efforts to dumb this down for yourself, but that still doesn't mean you have any real understanding of what you're talking about OR what happened in this situation.
No one, and I mean NO ONE, would opt to not complete coursework. No one would choose to miss out on the additional prestige and money towards retirement by dropping down in rank that hard.
It isn't as simple as E-9 to E-8. A CSM in the Army is as high of enlisted rank as you can earn besides Sergeant Major of The Army (also E-9). There had to be a reason for the man to do this, and it's anything but honorable.
The enlisted men in his company told us why; he pussed out and was too scared to deploy. Basically, he was fine being a weekend warrior until it was time to get called into combat. He (like
@extragreen ) is a traitorous bastard, dodging his obligation to answer the to call of duty.