Why is the man that Bakha bumps into in the street so angry?

The man is a caste Hindu, and he believes that physical contact with an outcaste will make him ritually polluted. He is on his way to do some business, and now he feels he must go home and bathe and change clothes so that he can purify himself. This means that he will be late for his meeting. He blames all of this on Bakha's carelessness, because Bakha did not stay to the side of the street and make himself known by calling out in advance.