I don't think the conviction matters to the point. They were convicted, but my point is that a suspicion that causes an investigation should probably warrant telling those who could be at risk, even if the investigation ends up going nowhere.
Not sure what you mean about the civil matter, CSAM offences are criminal, so I'd expect "innocent until proven guilty" to apply in this case. If you mean that for other civil matters there's no need to notify those at risk, I would agree, I doubt anything civil meets the bar of risk.
I think I misunderstood your point. It sounded like you were arguing against telling the scout group prior to the conviction, because they were innocent until proven guilty. But from your follow up, it sounds like you agree with telling the scout group prior to his conviction. In that case, I agree with you.
Not sure what you mean about the civil matter, CSAM offences are criminal, so I'd expect "innocent until proven guilty" to apply in this case. If you mean that for other civil matters there's no need to notify those at risk, I would agree, I doubt anything civil meets the bar of risk.