He left his post. He had left his post once before. Jackson was having control issues as most of these soldiers were voluntary. He needed to make a point that he was serious about desertion having already reversed numerous sentences similar to that of John Wood(s). There seems to be lots more about the story as my mother was a Wood. There were two other Woods involved in the story but I need to get it connected. William Obediah "Revolutionary Bill" Wood was Johns father. There was also a brother of John. They had expected that the sentence would be withdrawn because there was lots of support for not carrying out the shooting. The officers of the regiment wrote a letter to Jackson. Most expected the execution would never happen but they were wrong. There is even a little bit of a blurb that John Wood was completely innocent and was used by Jackson to get his mean to take him serious as he was having a major disciplinary problem with his troops.