Yes. This is my understanding as well. Gaslighting makes the person feel like the crazy one by setting up situations that make them question themselves (their memory, senses, ability to tell fact from fiction).

I haven't experienced gaslighting in therapy, although my first therapist kept changing her approach so often (out of ignorance--she was very new) that I often felt off balance and moody, which just made me look bad. In a way, she was recreating my childhood family dynamics--very chaotic and unpredictable--but she saw herself as only wanting to help, so it was just very crazymaking. I don't think it was intentional though. She just didn't know what she was doing.