[Turbo_pro]

This attorney's letter to the judge tells us two very important things.
First, the judge was fully within his rights and it was in fact his duty to determine if the plea bargain was a suitable resolution the this case. In requesting that the judge honor the plea the author of the letter is acknowledging that the sentence is not a predetermined quantity.
If the victims lawyer knows the sentence is not written in stone you must assume that Polanski's attorney was equally aware.

Second: the crime was so heinous that simply testifying to the particulars of the rape would constitute abuse.