The way in which Otto ends his significant treatment relationship leaves one open to feeling cheated and taken advantage of.
We can see him as manipulative conniving or even a sociopath who cares nothing about anyone. I however, have my doubts!
I think that there are many ways to understand Otto's use of treatment. He is a man who had almost no healthy role models of how to relate to others, of how to negotiate with others, or understand his (or others) own needs.
I think that his view of the world upon entering treatment, was use or be used by all. If in fact he was hoping to gain legal help from Don he would not believe that he could ask for and get helpful help. I do think he was desperately in need of help and was truly helped by his work with Don. How long he stayed in treatment and returned is tribute to that. I could see him feeling more comfortable framing his work in this cruel, humiliating way to restore a sense of loyalty to his belittling ,cruel parents. He may well have felt very uncomfortable having what might have been his first genuine relationship with anyone (Don). Stating that he used Don to gain his unstated goal of avoiding jail allows him not to feel indebted to or vulnerable to Don. If he "knew" (and could remind himself) that he was cheating Don all a long, he might have felt freer to use Don in treatment to get help on issues that were really bothering him. The balance was set up in his favor. I have seen many patients who unless they feel and are cheating you can't tolerate the dependent feeling that therapy brings up. They may do it though money or time or having a secret purposes for therapy.
It certainly does not feel good to be the recipient of this kind of a usurious relationship but if we look objectively at the work that Otto did we see a man who was very uncomfortable with all feelings his and everyone else's. Knowing what we do about his family it is no surprise. In fact he has done much better that we might predict. He has a great need not to feel and uses therapy to do so and still leave the relationship he came to Don to get help on. He is very over responsible for women, fears that they will and do fall apart and needed support to leave Sally. We see a clue to how much this man cares and needs to see himself (as he descibed )"as a good nice man" in the way he sets Sally up and moves her in. A truly uncaring man would just leave and do so much earlier.
I think that Otto cares to much. I think that he is very afraid that he is just as cold, cruel and self absorbed as his parents were and treated him. I think he found in Don a chance to see himself in a different light but out of loyalty and compliance with his family needed to find a secret way to destroy the bond and special relationship. I think that it was a big help to him to have Don reflections on how to have mutuality. It is a completely foreign concept to him. He expects to been seen as a empty thoughtless man and offers us every opportunity to see him this way. Knowing how the story unfolds I can see how often he invites Don to put him down and find him wanting. I think Don gave him a gift one that he couldn't acknowledge appreciating but one that will help him have a better life. Even thought we are offered the opportunity to see the treatment as spoiled I think it was an excellent piece of work. A sad man and case. Well done Don thank you for giving us this chance to learn together,