United7, Based on your new information, I kind of think that you are fine. In a situation where company B (dalal) comes after company C (dhoti) for your joining to A, you could be in problem. The situation is different since the client A is not C's client but B's and B is cool with it.

Anybody who should be concerned about your joining the company A is company B who will be losing the money. Based on the contract between B and A, it can fairly be assumed that the contract between B and C does not have a non-competition clause. Otherwise, company B would not do such a contract with A. I am now convinced that you are in a strong position but still you better take a lawyer's opinion. I believe the dhoti company does not have a strong case against you.

Why don't you call / e-mail and threaten that dhoti telling him that you will take a legal action against him instead for harrassing you? Looks like dhoti is trying to make some money by scaring you.