Patton got relieved of his command just for slapping a soldier. We prosecuted war criminals based on their treatment of POW's, and I'll bet that we prosecuted some of our own guys for mistreatement of POW's.
Here's the deal: there are times when an officer may need to disobey orders. But those times have to be extremely few and far between, else discipline collapses. If an officer makes the decision to do that, then he'd better be sure that he was right to do so, and he has to be willing to live with the consequences if he does so.
Maybe he was right to do what he did. But part of the price of being given the privilege of being an officer is to live with the repercussions of your actions. Is it fair? Well, maybe not. But its not "fair" for someone to get killed in the line of duty either, yet we expect it if it becomes necessary. LC West did what he thought was right, and maybe it was. He also knowingly disobeyed a standing order, and its now his duty to take his lumps for it. If it hadn't become public, he'd have gotten away with it, and no harm done. But since it has become public, he's got to pay for it.
The magnitude of the punishment should be open to debate. But the fact that he should be punished is an easy call.