Aw okay. No wonder I was so confused. So does it look like the secret service actually got the coins or no? Or is it just too hard to track manually because of the mixing service?
It is possible to track, but it is difficult.
It depends on this secret service capabilities.
There is no way to be fully anonymous in bitcoin network, but you can be pseudo anonymous doing as this user did. he tried to hide, but it is not 100%