Not enough airholes in the sleeping bag?
He wrapped the general up in a sleeping bag and tied him up with electrical wire. He said he was acting within the regulations. The jury clearly accepted that.
Now imagine you were in Colorado Springs, not western Iraq. You and a group of large, strong men and women beat someone repeatedly, then wrap him up in a sleeping bag, tie him up, and let him suffocate.
You're sitting on a jury, hearing these facts. Is this premeditated murder or mere negligence? Odds are, you vote for murder.
The difference is that this officer asserted he was acting on orders. The jury bought it. That means that some of the responsibility for this death, a clear violation of the Geneva Convention, moves further up the chain of command.