The main beef on Thomas Harlan was that when he was passing through, on the way to see his father, when he ran into Downard and MacKenzie. He looked suspicious to them and vice versa. Harlan was invited by them and was treated with a dinner, etc., but the time together was one of talk on war, life, etc. Actually all of them were cautious on how they interacted. Harlan not wanting to give away that he was deserting and our two villans who did not want to give up their identity.
Harlan felt very uncomfortable in their presence and heard things that made him leave. He was never harmed nor threatened. When he felt uncomfortable, he found an opporunity to leave and did so.
Looking back at it, Harlan's character was nothing more to the trial but making Doward and Mackenzie look good, even though Harlan could care less about them.
Harlan's character was one who was very cautious in how he interacted with others and quiet. That was one reason for not saying a whole lot, especially in conversations.
One side note. While the trial was not in session, we learned that Mr. Harlan also had a talent when it came to sewing. Reading the books and discussing some of the projects were great. Thank you ladies!