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How do we deal with questions like this, that are in the end medical questions. I'm not thinking about off-topic/on-topic, but about liability. Wrong medical advice on this site could cause legal trouble.
Is there an official SO policy about that?
Use the same guidelines that you would for legal questions, and do has you have done in that question.
If you think it's a medical/legal problem simply state that fact. Don't offer any more advice other than that the OP consults a doctor/lawyer.