Is Oedipus Himself Responsible For His Downfall In The Play "Oedipus Rex"?

This is not a simple question to answer. On one hand we see Oedipus saying, "…but the blinding hand was my own" and on the other, he says, "What web has God been weaving for me?" But most of the critics agree upon the role of fate in the downfall of Oedipus. He is a man who tried his utmost to escape the deadly fate written for him even before his birth. Not only he but his mother, Jocaste also tried her level best to avoid the undesired encounter with fate.
Unlike the other Greek legends, oracle about Oedipus was unconditional. There were no "ifs" and "buts" in the oracle. The oracle received by his mother was "he will kill his father and marry his mother". There was no condition put upon Oedipus that "IF" he will do this then he will kill his father and marry his mother. So, the decision of fate was already there.
We see him running away from the house of his supposed parents, just to get away from the oracle. But instead, he committed the murder of his father unknowingly. And to make the things even worse, he came to the city of his birth. His intelligence proved to be Achilles' heel for him. He was made the king and the husband of his mother.
In this way, we can say that Oedipus, to a large extent, was not responsible for his downfall.