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

Although Kaka Mahajani's friend had resolved not to bow his head to Sai Baba, this resolve was broken during his very first darshan. As Chapter 35 recounts, when the friend set foot on the mosque step, Baba looked at him and spoke sweet words, asking, "Why have you come in this manner?" The friend was astonished because the charming tone of Baba's voice was a perfect imitation of his own deceased father's vocal style. Hearing speech as if from his father's mouth caused the friend to melt inside, forget his previous vow, and spontaneously bow his head at Baba's feet.