Yes, but they didn't hack into the wallet. They basically found the person who was in-charge of the wallet and forced their hand (read: civil forfeiture) in order to gain access to the bitcoin.
Concealment is also generally grounds for tolling the statute.
And in some states, if criminal acts are related, the statute for the entire body of crimes doesn't begin until the last related criminal act.
See for a breakdown by state: https://criminal.findlaw.com/criminal-law-basics/time-limits...
In the U.S., they can compel someone to provide a password if doing so would not violate the owner's Constitutional rights (such as, for example, if it would be self-incriminatory). Courts in the U.S. have different thresholds at when that line is crossed, but a bright line rule is that providing a password is not self-incriminatory if the criminal case has already been litigated to its conclusion (i.e., the suspect has either been found or plead guilty, or was found not-guilty and double-jeopardy protections apply).
It wasn't clear how the "agreement" was reached and what coersion was involved.