The very last scene filmed in the movie was the one where Landon finally visited Clay Gephardt in the rehabilitation center before performing in the play. This was the "cover set" which they never needed. A "cover set" is an internal scene (a scene filmed inside on a soundstage) that is set aside to be shot on short notice on days when weather does not allow scheduled location shooting. Adam Shankman, the director, revealed that they had the actor on hold through the entire rest of the production and it cost them a fortune because he wasn't needed and was finally used when everything else was done.
Mandy Moore's final scenes were as follows: she and Landon passed each other in a school hallway after a fight (at the end of the play practice montage). The scenes where she was in bed and talked to her father.