Is Oedipus an innocent victim of an unjust fate or does he bear some responsibility in the outcome of his life?

I believe that Oedipus was indeed an innocent victim of his fate UNTIL he met the old man (his father) at the fork in the roads- note that this can be taken as a symbol of freewill- where he angrily murdered the man. Ultimately, this led to Oedipus' demise.