And that would also validate control of the same address at some point.
One thing to bear in mind is that it could have been a contractor who worked for the FBI. Someone at an external firm hired to do the job. Or just a tech at the FBI.
The FBI would still be liable, but would also potentially point their ire at the thief and criminal who did so, under contract.
A law firm might pro-bono the detective work, to see just who spent that coin, if anyone did.
If you obtained or spent the bitcoin with a company or person that you are still able to contact, you should be able to get an address.