Crypto has a strong reputation as a haven for money laundering, drug sales... So if any of the Mexican/South American drug cartels lost a lot of money Sam and the other top management of those companies could end up dead.
In this case, I’d bet that he’s safe if he ends up in federal custody since being in prison is also effective punishment from this perspective. If not, it’s easy to imagine something happening to him if he tries to hide somewhere since the message “you can’t run far enough” will heard by everyone in that world.