Broker threatening since the final deal didn’t go through him

So my mother had a property in Kerala which she wanted to sell. She approached a local broker and asked him to get suitable buyer(since she lives in another state, it was impossible for us to find a buyer ourselves). But the brokers were unsuccessful for quite sometime. And one of the buyer whom broker had got initially approached us later to buy it mentioning they had a fallout with our broker and they don't want to deal through him(and this buyer approached us later though a new broker). Since we wanted to sell it due to financial debts my mother had(she’s retired hence no more income), we finalised the deal and sold it and paid brokerage to this new broker. Now the first broker is making huge fuss. He is continuously calling, sending voice notes threatening that I won’t leave you alone and telling my mother “I have means of bringing you back to Kerala and I don’t care if you are a senior citizen or unwell”. So I wanted opinions from this forum that is what he is saying correct? Can he do that? Does he has any means to torture my mother via phone calls and WhatsApp and regarding whatever he said about he has means? We had no written agreement with him prior to selling the property. Also, legally that property is now with new owners and we have nothing left there in the city, so can he do anything harm to her? Sorry for such a long query. Hoping for some suggestions. Thanks