I don't think I am giving him latitude, if your job was selling to people and a customer had expressed interest in your product and had agreed to wait for you to call back would you in a million years stop to think "maybe he was lying to me, when he said he wanted to call me another type he wasn't telling the truth, I'd better check the database to see if he doesn't want me to call"?

Other than random, unexpected cases of people trying to trick you, any customer in the world would, if they changed their mind about being interested, wait for the call back and say it then, not contact someone else at the company to be put on a do not call list.