There is always a choice in what you say and what you do. No one forced him to deny Jesus three times. He chose to in order to protect himself, but it was not something that he was forced to do. He could have made different choices that would have hurt him.
The story of Judas is important for Christians. We look to Judas and see a good man who turned into a bad one by turning on his savior. I think that the argument that Judas "had no choice" is one that is rather shortsighted. Of course he could have chosen not to do what he did.
Judas realistically did have a choice. He chose to betray Jesus and was not a predestined thing at all. He made the choices to do what he did and he lived with it. Judas was consumed with greed and wanted to profit from the group instead of following Jesus. He could have easily chose not to do this but did not.
What Judas did may have been understandable and may even have been necessary in the course of human history given what it led to, but there is always a choice. Judas gave away his friend, perhaps for the best of motives, but he still allowed himself to make that decision.
I believe we all make choices everyday. We may feel as though we only have one real choice, but in reality we have many choices and sometimes the best one, isn't the easy one. Of course Judas had a choice, would either have ended in his death, maybe so, but that doesn't mean he didn't have a choice.