We have had a similar thing happen, but the plate is not totally destroyed.
We were sailing with 2 reefs and then suddenly the jib unfurled itself. Tried with the motor and it was turning but the jib kept unfurling. Came right off the wind, loose sheets and the motor was able to furl it in. Carried on the next bay with staysail.
Took the two halves of the furler-foil drive apart and saw that our plate actually has two big slots for the manual pin. What had happened is that the manual pin had come out of the slot in the plate and the sail unfurled. That slot in the plate is distorted and now useless. I reassembled it so the manual pin is in the other undestroyed slot and its all working except that the problem we have now is that the manual furling pin is bent and we can't pull it up to manually furl the jib.
If the motor fails we'll have to drop it.
Anybody have that experience and how did you solve it ?