Whoops, my question was posted incomplete.
As I was saying (!), in the examples there is agreement between the indirect object and the participle:
La télé? Oui, Marc l'a regardée
Ces épisodes? Il les avait déjà vus
If this is the case, then shouldn't 'Tu lui as parlé' translate as 'You talked to him', BUT 'Tu lui as parlée translate as 'You talked to her'?