Why did Kaka Mahajani's friend, who was against idol worship, end up bowing down to Sai Baba?

Kaka Mahajani's friend was a devotee of the formless and averse to idol worship, visiting Shirdi with the firm conditions that he would not bow his head or offer Dakshina. However, this resolve was completely forgotten upon meeting Sai Baba. As described in Chapter 35, when the friend entered the mosque, Baba spoke to him in a sweet tone. The friend was astonished because Baba's voice and way of speaking were a perfect imitation of his own deceased father's. Hearing speech as if from his father's mouth caused the friend to melt inside, forget his previous determination, and spontaneously bow his head at Baba's feet.