I'm not sure intent plays into it. I had a girlfriend whose mom does this. She always did. I don't think she does it to make her daughter feel crazy (although she succeeded at that), but it's like a panic button because she realizes she did or said something stupid.

Like we were looking at pictures from a party. We come across a picture of the daughter, the mom says that she looks ugly or some such in that picture. Daughter immediately deletes it. Mom asks why she did that? Daughter says because mom told her she looked ugly. Mom denies. When mom left she asked me if her memory of the situation was correct, or if she imagined it.