Some people learn more slowly than others,yet it's often the teachers who profess to be the most enthusiastic and caring in their advertisements who don't have the patience when you hold on a crotchet which shoudn't be held(this was a direct experience of mine) and use this as an excuse not to teach the whole piece! Any piece can be broken down into constituent parts and I don't agree that fingering is the pupil's responsibility either:it's part of why I pay a teacher handsomely to look at my hands and direct a pencil con moto across the ledger lines..
I too have had pieces taken away from me (for the moment) because of reasons incomprehensible for me. But that is the whole point of having a teacher... Of course we should trust ourselves, but the point of having someone more experienced teaching us is to trust their judgement and learn with it. Perhaps it was not only the note you held, but what this meant inside the context... The process of learning is a very difficult one. Everyone says it is difficult to be a master, a teacher, but it is also very difficult to be a student. One has to to be very humble.
That being said, I don't have a clue if that's your case. I'm not pointing fingers. I don't know you nor your teacher, so well, can't say anything. But you just know when you're in the presence of a master, a great pedagogue... In my case, the only one I can truly speak of, I already jumped form a Chopin Scherzo to a Bach 2 hand invention. It was excruciatingly frustrating, yes, but after it all I learned a lot. IMO that's the reason we have a teacher. To approach things in ways we would never approach.