After learning the truth from Jog, how did Dev react and rationalize his mistake?

Upon reading Jog's letter which detailed Baba's explanation, Dev was overcome with emotion. Chapter 40 describes his eyes overflowing with love and his mind filling with regret. He exclaimed, "Shame, shame! I blamed Sai in vain!" and felt very dejected. He then rationalized his inability to recognize Baba by recalling the sequence of events. He noted that the Sanyasi had first appeared to collect funds for cow protection before the Udyapan invitation was even extended to Baba. This prior context led him to believe the Sanyasi was just an ordinary person. Dev admitted that he forgot to pay attention to Baba's specific words that "two others will come with me," which could have been a clue. He concluded that this initial encounter for a different purpose created the "delusion" that prevented him from seeing the truth.