Working on being able to depend on yourself will help you with this, instead of trying to place all responsibility on others for knowing everything or having prescience. Your T does know what she's doing. Sometimes people make mistakes. Maybe your T did, maybe she didn't. Maybe she tried an approach in therapy with a new client and it seemed to work well but maybe it needs to be fine tuned so she shifts the direction a bit. I don't necessarily consider these to be mistakes, but the trial and error that is part of most any endeavor. I think if you can work toward developing your own feeling of safety and confidence that you know what you are doing then it won't seem so disturbing when someone else in your life appears to not be absolutely certain of what they are doing. I think it would be good to discuss with your T your need to have someone in your relationship be responsible, make mistakes, mess up, or be at fault. You seem so eager to assign "blame" to someone, whether your T or yourself. Maybe therapy is just an organic thing, and it grows and changes with time, and there is no one who "messed up." You seem to have gotten so much out of therapy with this T, rainbow. Why do you want to pronounce it a failure? Seems kind of harsh.

The person who "allows" a T to make mistakes is the client. The client has to judge if the mistake is serious enough to harm the therapy. If it's a serious mistake, they can either choose to work through it (allow the mistake) or leave therapy (not allow the mistake). If it's not that serious, perhaps they can reframe it so they don't view it in such a negative light (i.e. stop viewing it as a "mistake") or just let sleeping dogs lie and get on with therapy. Rainbow, if the mistakes you refer to are serious, I urge you to work through them with your T.