Make room for the other version
Ask what the other person understood before assuming that you are arguing about the same facts. For a message about how to send a respectful cross faith holiday greeting, use this factual base: name the event, role, custom, language, access need, or shared rule and distinguish impact from assumed intent.
Correct the record precisely
Correct only what you can support, acknowledge any real impact, and propose a practical way to prevent repetition. Ask for the correct practice or a concrete change and give the relevant person room to explain. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Agree on a testable next step
Do not speak for a whole community, demand education from one person, or use public shame as the first step. Use safeguarding, accessibility, anti-discrimination, security, or emergency routes when rights or safety are at risk. Do not recruit an audience, publish private evidence, or turn a misunderstanding into a campaign about character.