What role did Jog play in the misunderstanding and subsequent resolution between Dev and Sai Baba?

Jog acted as the essential intermediary who both conveyed the problem and delivered the resolution. According to Chapter 40, after Dev felt disappointed, he wrote a letter to Jog detailing his belief that Baba had failed to keep His word. Jog then took this letter and "communicated the entire account at Sai's feet." After hearing Baba's explanation—that He had attended as a Sanyasi—Jog was filled with joy. He then performed his final, crucial role by sending a detailed letter back to Dev, happily informing him of the truth. This letter from Jog is what finally dispelled Dev's delusion and prompted his feelings of love and remorse.