Don't take offense at what John posted. It was a reasonable reading based on circumstantial but factual information he gathered: one (possibly two) with a history of desertion, one oath taker, NCO's, units, etc. John's info is incredibly helpful and detailed and I've not noticed bias in his postings.
The devil is in the details and it doesn't appear that we have much in the way of contrasting accounts presented so far to work from. Were they headed home with weapons without assembling for parole? If parole was to be given in Wittsburg the next day (based on the timeline another posted) and they were headed away from it (~80 miles north), would they have been taken for guerrillas and shot? Or were they headed for it or another parole point, and shot anyway? Did they really lay down arms when confronted? (Need some corraboration that they were passive, if they did any shooting with the war over I don't think that would have been good for them.) Were some/all wearing enough Union uniform that they were in trouble on that basis? Were any already identified as guerrillas to be shot on sight?
What is missing is some explanation of exactly who shot the men and the professed justification for doing so (if any) no matter how thin or contrived it might be. With that information one could compare stories and weigh them.
I'm not trying to imply anything about the men with the questions asked. In answering one could possibly rule out any justification for the executions or find that they weren't as innocent as supposed. Anything seems possible at the moment.