I have had this experience several times in my life; I come across clear enough evidence that settles for me an issue I had seen long disputed. At that point my choice is to either go back and try to persuade disputants, or to continue on to explore the new issues that this settlement raises. As Eliezer implicitly advises, after a short detour to tell a few disputants, I have usually chosen this second route. This is one explanation for the existence of settled but still disputed issues; people who learn the answer leave the conversation.
See also this old Robin Hanson comment: