A Good Broker to Agent relationship should begin with a contract that everyone understands and agrees with to avoid this type of behavior. I have worked before with a Broker that gave a strong handshake but when it came to move on, the Broker's handshake turned into a hammer. He kept all of my sales I had on the board. However, because he did not know about the clients I was working with, those stayed with me. In the end, I lost over $28k in commissions and learned a valuable lesson. Again, a contract should avoid all of this. Without one you could be walking away from all of your sales on the board, current listings and buyers should you decide to leave. Also, most Brokers do not ask for a weekly report showing all of the buyers and sellers you picked up including their name & numbers as they should so they do know who you are working with and where you business is coming from. I only use this info for data. It helps me with advertising.
So I have been on both sides of the fence. This is why I will not work for another Broker or hire an Agent without a contract. It keeps things simple without any misunderstandings. I want all parties to part feeling they were treated fairly in the split.