re: Dr. Harvey Risch just said Covid has 19 genetic letters from a 2017 Moderna patent HMSH3

That's fair. We shouldn't take Gemini/other AI response as a final word on a genetics question, but that leaves us still needing to do what we'd need to do otherwise - try to figure out how to interpret technical information without personal competence in a domain.

In this case, the authors of the '22 paper didn't claim they'd proven Moderna engineered the virus. They proposed a possible explanation for the sequence match that they said needed further investigation, so the next step could be to look into what geneticists have found since that 2022 paper. Then you might get a sense of whether the match distinguishes lab origin vs. other explanations for it.