I think they have selective memory. They select what they want to remember. If there is any benefit for them by denying, they will deny. If there is any benefit for them to remember, they'll remember.

Zlata, I give you credit for watering their plants. If anyone said to me what your mother said to you about stealing from her, I would have walked out and never returned. My my NPmother said something similar to me. She had a cabinet that she locked always, carried the key with her. She has taken out of it a large plastic bag half filled with white pills. She was shaking the bag in my face and said they are sleeping pills, and when she had enough of life she will take them all. I was talking to their  Dr., and mentioned to her what my NPmother said because I was worried. Wouldn't you know the woman told my mother? Next time when I was visiting, my NPmother said: You were rummaging through my stuff, huh? The Dr told me about it. I was mortified that my own mother would accuse me of breaking into her locked cabinet... I've never forgiven her for that. That was the one before the last straw. After the last straw I went NC. They are nasty people. Dolly