Name the impact without exaggerating it
Describe who had to wait, worry, redo work, spend money, or make a choice with incomplete information. For a message about how to discuss a values conflict with a friend, use this factual base: use one or two recent examples and name the trust, effort, money, or inclusion issue they created.
Make repair practical
Offer the repair you can actually complete, with ownership, timing, and any limit stated honestly. Ask how your friend understood the situation and propose one change that can be tested. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Let future behavior carry the proof
Do not assemble mutual friends, post indirect messages, or use confidential information as evidence. Stop direct contact and use appropriate support when there are threats, stalking, coercion, or safety concerns. A promise inside a message is weaker than a visible change in what you do after it.