Except this is not how DeFi and dApps work. The network is decentralized. At no point was any unauthorized access to a system performed. This is not the same as entering private property through an unlocked door, or using SQL injection to gain unauthorized access to a system.
This is not to say Medjedovic is innocent; he made extortionist threats, and gleefully admitted he stole money from people, so wire fraud charges seem obvious. As you say, the courts care about intent, and his intent was clear. But you can't apply the normal charges of accessing a computer without authorization here.