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 ask for a disability accommodation at work, use this factual base: use the person's description, note the access barrier or practical need, and avoid guessing about severity.
Correct the record precisely
Correct only what you can support, acknowledge any real impact, and propose a practical way to prevent repetition. Ask which accommodation or form of help is useful and follow through without making it a favor. 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 demand medical proof in a personal relationship, offer cures, or frame disability as inspiration. Use qualified clinical or emergency care for urgent health concerns and the proper rights process for denied accommodations. Do not recruit an audience, publish private evidence, or turn a misunderstanding into a campaign about character.