So he ran a DDoS network that wasn't behind Cloudflare, but used Cloudflare to stop his website being DDoSed by competitors, and this means Cloudflare was helping him DDoS others? No, it means Cloudflare was helping keep his website up, in a neutral manner. In other words, exactly what Cloudflare have stated their policy is. Now if Cloudflare allowed him to run DDoS code on its Workers, then yes, that's Cloudflare he…
This kind of pedantic reasoning could be applied to any forum: the forum software doesn't do any active harm to anyone. It "only" serves to coordinate the bad actors.
Just like the DDoS site does. So, how is it different?