The star witness in Chevron Corp.’s mega tort counter trial has been Alberto Guerra, a former Ecuadorian judge now living in an unprecedented private witness protection program funded by Chevron.

Chevron alleges that Guerra arranged for a group of Ecuadorian environmental plaintiffs and their lawyers to bribe an Ecuadoran judge in return for a bogus $19 billion judgment in February 2011. Chevron’s opponents — now battling Chevron’s fraud claims in federal court in New York — insist it’s Guerra’s story that’s bogus.