George Clyde and Daniel Holt

No, it wasn't because of Holt's friendship with Jake. If you remember, when Jack Bull lay wounded in the dugout, George said he'd go get a doctor and come back. What was unsaid at the time was that everyone knew that this was George's way of cutting out. George had already wanted to leave Jack Bull for dead and get away from the Yankees who were combing the area, but Jake insisted on caring for his good friend.

So when George made the offer to go get the doctor it was a naked lie. Jake and Holt saw through it but had too much character to call him a liar outright. George down deep knew they saw through him, but he wanted to get away too badly to care. He wouldn't have done it at the start of their war, but they'd had some hard times and a lot of fighting and killing and near-dying, and he was a different man now. Jake and Holt were still men of honor though and stayed to see to Jack Bull and bury him.

Of course, George took the chance to run. When Jake and Holt came upon him at the encampment later, Holt definitely resented that George had broken their bond of brotherhood and honor. Particularly since Holt had not only saved George in the past, but Holt had been fighting for a cause that would keep him a slave, all for George. So Holt definitely was wounded that George abandoned him to save his own skin. Holt, who was a good and decent man, saw that Jake was also a man of strong character. Holt saw he could trust Jake, and became the friend to Jake that he had been to George.