he was not arrested for just making a tool. and then handing it off and not being part of its latter use..
he was found to have taken a active and involved part its use, and also he received a fee from facilitating the vietnam hackers transactions..
Let’s wait for the actual case then, because none of this is stated in the official press release
1. Apparently 7 billion dollars passed trough the service, with 1 billion being of criminal origins. Then the question remains if he actually participated actively or passively(by running a service criminals abused). If simply providing this service will be judged as illegal then my point remains as above. If he actively was part of this and gets judged individually then you’re right.
1 https://www.fiod.nl/arrest-of-suspected-developer-of-tornado-cash/