> I certainly didn't memorize them back then.

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.

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.