Do not rejoice when your enemy falls, and let not your heart be glad when he stumbles,
(Pro 24:17 ESV)
This passage almost certainly applies to general life circumstances about people falling on hard times, or bringing about their own demise. I want to look at it from a different perspective that I think is an equally valid insight from this verse.
Suppose you are having a conversation with a friend on some matter of truth. They disagree with you (taking the position of “enemy” broadly speaking). As you discuss the matter it becomes clear that your friend either has not thought through their views, or their views are not based on good evidence or reason, or in some cases perhaps they are just wrong. For some people the realization that they are at an advantageous position in a conversation is their cue to run the victory lap and celebrate their own intellectual superiority.
Don’t do this! When you have shown that your friends views range from “poorly grounded” to just plain false make it easy for your friend to change their views without losing their dignity. Never celebrate a demonstration of their ill-informed beliefs or your own well-established beliefs. Make every conversation a conversation that everybody can walk away from with their heads held high.