Doris
That takes me back a few months to when Mum was at home with Dad and he rang frequently for help, because Mum was insisting she wanted to go home, getting agitated and tearful about being in a "strange place" - they had lived there for 35 years.
I used to go in and point to an ornament or piece of furniture and ask who they belonged to, she knew they were hers, so I said if they were her things she must be in her own home. It took a few minutes pointing out various objects until it dawned on her that she must live there. I then quickly changed the subject and she settled again.
There is no logic to their thinking in that situation and it must be another scary situation for them, maybe that explains your friends verbal aggression.
Other people on the site have said this happens with their relatives as well, it seems a very common theme with AD sufferers.
Sorry I can't be of much help, but at least you know you are not alone with this problem.
Kathleen