Actually you know at the very end he was guilty. She pushes his car over a cliff and then stages a trial at the house. Her husband think she´s crazy and tries to help the man. She takes him to the cliff in the morning but she cannot throw him over. He then admits he was her jailer and explains why he started doing it.
It´s a very strong film and in fact the tension between the woman and her husband surface during this crisis. Turns out he was the leader of some kind of resistance movement against the Sout American reign, but she was the one who was captured and tortured. When she finally got out of prison camps and went home to him, she found him in bed with another woman. She has never really forgiven him and when he rises to power in their country she starts to despise him and he is afraid of her power over him, plus he feels guilty. This is why he is in denial of the man that comes to their house and is in fact her jailer.
http://www.imdb.com/title/tt0109579/plotsummary http://www.imdb.com/title/tt0071910/combined