It is entirely likely that had he given them notice and then 6 months to prepare, they would have spent the entire 6 months suing him and trying to get him sile

It is entirely likely that had he given them notice and then 6 months to prepare, they would have spent the entire 6 months suing him and trying to get him silenced by court order. The problem would then still exist but he would be bankrupt and unable to warn anyone. Our legal structure creates situations where the "right thing" sometimes has to be balanced against the potential for personal ruin, so it turns into the "rightest" thing given the circumstances.