is a coincidence. He felt guilty.
He didn’t stand to get much of a “deal” for testifying stateside.
Any sort of “plea bargain” offered by a district attorney or prosecutor is actually a form of witness intimidation, or at a minimum, tampering with a witness.
While defendants do have the right to remain silent, and not to incriminate themselves, they may testify on their own behalf in court, in which case they are witnesses, not to be discouraged from raising an actual defense to the criminal accusations against them, or encouraged or induced to plead guilty or refrain from testifying.
The defendant must be free of cruel and unusual punishment and the subtle but forcible subornation of perjury that goes along with that in order to have a fair trial.