As Oedipus was unable to avoid fulfilling the terrible prophecy laid upon him at birth, we can see him as being powerlessly subjected to his fate.
When we consider the great lengths that Oedipus went to in order to escape killing his father and marrying his mother, we can clearly see that his will was bent on mastering his destiny. He did not want to fulfill the prophecy. He did not want to be dominated by a negative fate.
The evidence of Oedipus' efforts can be found in the fact that he leaves the parents who raised him in order to save them (and to avoid fulfilling the prophecy). He fails in this effort, offering some strong proof that he is a "victim of fate".
He learns that he has killed his father, married his mother, and had children with her; his wife-mother Jocasta...
If Oedipus can be seen as striving against the prophecy yet fulfilling it regardless of his most strenuous efforts, we can argue that he is not to blame for what happens. He is a victim, like Jocasta.
His remorse, as well, points to his status as victim. He was never in control of events, but was only an ignorant player in the drama of his life. He was saved as a child only to bring shame and a curse to his family.
Let him die who took off the fierce fetters,
feeding off my feet, and rescued and saved
me from my death, no good deed for me!
For if I had died then,
I would not have brought (1380)
so much pain to my friends or me!
He could not escape his destiny. He thought running away would help him, would change his fate, but in the end it was the one things that greatly contributed to his inevitable doom. I feel for him, he tried. But it is a piece that shows just how powerful destiny is and just how small and powerless we may very well be.