What was the primary reason that the man who was averse to idol worship ultimately bowed down to Sai Baba?

The primary reason for the man's change of heart, as described in Chapter 35, was a powerful, personal auditory experience. Though he was a firm devotee of the formless and had resolved not to bow, this conviction was overcome when he heard Sai Baba speak. Baba's voice and tone were an exact replica of the man's deceased father. The text highlights this, stating, 'Hearing such speech as if from his father's mouth, the friend melted inside; He bowed his head at Baba's feet, forgetting his previous resolve.' This uncanny and deeply emotional connection completely bypassed his intellectual objections and led to his spontaneous act of reverence.