Here is a long winded legalistic side of Polanski's story. His lawyer at the time now says the judge said in closed session he wanted Polanski to be sentenced to another 48 days in prison (after 42), waive his right to a hearing on that sentence, waive his right to a deportation hearing (which requirement may have been judicial misconduct), and voluntarily deport himself.

Polanski chose to voluntarily deport himself.