Of course they're allowed to make mistakes. They're human. We can choose whether or not to forgive them for their mistakes, just as they can choose whether or not to own them.

My philosophy on it is that if I would forgive a loved one for something, I might as well forgive T. My relationship with him is an excellent place to practice both confronting things I think are mistakes and forgiveness.

There are unforgivable things for me, but they're pretty extreme. If T did something completely inappropriate (which I can't even begin to imagine him doing), I would be hard pressed to forgive. But a misstep in the therapy process? Almost always forgivable to me, unless it's constantly repeated.