Two problems with that assertion. First, it does not matter _why_ the executions were ordered in establishing the irrefutable fact that they were done without the proper procedures even under military justice.
Second, we do know "why" they were ordered - Milroy was seeking a loot and found the person of Moses Pittman to provide him a means to one. He asked Pittman (who was apparently very disliked by the locals as an illiterate ne'er do well and scam artist) to draft up an "enemies list" of all the people in the area he didn't like, which then served as a basis for Milroy's death lists. Pittman was "rewarded," of course, by being given a few extras to torture to death.
There are legitimate reasons, such as those I mentioned, for all of his actions, as defined in the Articles of War.
There is NEVER a legitimate reason in the United States Military to execute by torture and all official executions must occur through some form of adjudication procedure within the military system. Tortures do sometimes slip by with men on the field and low level soldiers like at Abu-Gharib, but death by torture is always illegal and especially so when fully authorized by a commanding general. What Milroy did would be akin to a document surfacing that showed Tommy Franks ordering Lynddie England to not only defile her prisoners but then chop their heads off and dispose of the bodies once she got her "entertainment" out of the way.
Many of the charges of "atrocities" are without a firm foundation, and we usually find when some sort of "documentation" is posted, it's from somebody's granddaddy's journal written 40 years after the fact (or conversely, in some obscure archive that nobody can easily access).
Well, fortunately for you neither is the case with Milroy. The documents are all in the official records of the US Government written by his hand on army stationary. They are also easily obtained from the largest and most accessible document repository in the United States: the national archives.
Makes me wish we had the damned Communists back.
Article 12 left that up to the "chief commander." There was no requirement to give, for instance, bushwhackers and guerrillas "due process." Your premise that the executions were done "without proper procedures" is unsubstantiated.
"Second, we do know "why" they were ordered - Milroy was seeking a loot and found the person of Moses Pittman to provide him a means to one. He asked Pittman (who was apparently very disliked by the locals as an illiterate ne'er do well and scam artist) to draft up an "enemies list" of all the people in the area he didn't like, which then served as a basis for Milroy's death lists. Pittman was "rewarded," of course, by being given a few extras to torture to death."
All from that order you posted?? Wow! You have concocted a very imaginative story. Have you ever considered writing Civil War historical fiction?
Your post of Milroy's order doesn't say the United States executed anyone by torture. I believe it says that two bushwhackers were turned over to Mr. Pittman, who, for all you or I know, may have represented the civilian authority in the area. As I said in a much earlier post, when you brought this up, it sounds to me like there were some scores being settled.