Protected list in commercial real estate. Do I have anything to stand on with Protective List?

Signed 1 year contract he showed prop. to three prospects. Six months in I gave him a lead from a friend of mine. He showed the prop. 5 times, no price mentioned and no action. He placed my co. on a protective list for six months. Party still interested. Tried to talk to him about commisions he offered lowering his com. to 3% from 5.5. If deal goes through it may be completed in two to three months. My stance is he did not bring the prospect to the table.