If the owner has set a floor, then the broker is stuck and will try to sell it at that price. After a while, the broker will ask that the listing not be renewed with him. He is wasting his time trying to defend the indefensable.
Most brokers would rather see a quick cheap sale rather than try to squeeze the last time out of a sale. After all, they only get 10% of that last dime, if that. Bird in hand...