Briefly, from the information I have, Griner displayed a bad attitude at the time of the discovery of Hash oil in Griner's luggage, and for about a day and a half afterward.
Apparently, Griner was provided a Russian lawyer for advise/representation.
After this, Griner admitted guilt and apologized for the infraction and attitude. At that point Griner was scheduled to serve less than six months in jail (not prison), pay a fine and be deported from Russia.
THEN the US State Department and Biden got involved and shot their big mouths off, and insisted on Mainstream Media Front Page Diplomacy, rather than the standard private conversations between diplomats.
So Griner, and Griner's supporters, can thank Biden and State for eight years hard labor, and no swaps.
I'm not suprized by that considering the way Brandon's administration was commenting about the russian justice system:
"U.S. Secretary of State Antony Blinken released a statement Wednesday reiterating that the nation is working to secure Griner’s release and calling the move to a penal colony another “injustice” committed against Griner by the Russian state. “Following a sham trial and the unjust sentencing of Brittney Griner, Moscow is transferring her from a prison in Moscow to a remote penal colony,” Blinken said. “It is another injustice layered on her ongoing unjust and wrongful detention......