The physical universe advances from state to state, but we define still can call certain behaviors illegal.
Alright, please go ahead and define under what legal pretext this guy's behavior might be illegal.
There are other cases where interacting the blockchain is illegal in a very clear manner. Example: if I know an Iranian or North Korean entity has the keys to an Ethereum wallet, and if I send USDT to that wallet as a Western citizen, that is very illegal due to sanctions.
There is a US indictment which lays out the basics of the which laws Medjedovic is accused of breaking.
https://www.justice.gov/usao-edny/pr/canadian-national-charg...