Your friend would have changed the electric plate that's on top of the valve body.
Which he probably didn't have to replace. Should have topped it up with oil and should have been fine if he didn't take it on a long drive.

There is a lever on the valve body that catches on the gear shifter most deffinetly that has not been placed right that's why the car is stuck in park.

Drain your oil remove the valve body find the little lever and the shifter catch, then line them up together and reinstall the valve body, if this is confusing you pm me and I can send you some
Documents on how to correctly install this.