This is a great question and let me give you a few perspectives on this topic.
First, the answer to this question rests partially on historical context. In our modern context, we would probably answer the question in the negative. We would probably say that we need to do something intentionally to be held liable. But as you can see from the story of Oedipus and his life, some cultures will have a different answer.
Second, intentionality is important, but the whole personality of the individual is also important when answering a question like this. So, Oedipus did not intentionally marry his mother and kill his father, but he was a proud man. It was his pride that led him to act in a certain way and make certain choices. So, we can argue that while Oedipus did not knowingly do certain things, but his pride makes him liable, because pride causes certain actions to take place. This is certainly Sophocles's point.