How did Sai Baba's interactions with Kaka Mahajani's friend challenge the man's initial vows not to bow or give Dakshina?

Sai Baba masterfully challenged the man's vows through both direct and indirect means. As Chapter 35 explains, the friend's first vow—not to bow his head—was shattered almost immediately. Upon hearing Baba speak in a tone that was an exact imitation of his deceased father's, the friend was so deeply moved that he 'melted inside' and bowed at Baba's feet, forgetting his resolve. His second vow, not to give Dakshina, was challenged more subtly. Baba twice asked for Dakshina, but only from Kaka Mahajani, pointedly ignoring the friend. This exclusion made the friend feel 'restless in his mind,' creating a longing to give an offering that he had previously sworn he would never make.