Players can and will invent promises out of thin air. I just had a youngster with a loan status of unavailable for loan scream at me for breaking a promise not to loan him. I look and I have a completed loan promise to him that starts and ends on that day, I reloaded a save from the day before to check my promises and what do you know. There was no promise to that player at all. The player just invented it to try and force a move.