Although off topic, if I were Boris Becker, by hook or by crook, I’d get myself back to Germany and live out my years in freedom there. Germany has a habit of refusing to extradite its citizens.
Boris surrendered his passport such that he would not be a flight risk – but had I been the judge at his trial, I’d have remanded him in custody, given that it is almost certain he will be jailed (given the amount of money involved in his deception) and the difficulty in getting him back from Germany.