A friend of my husband is confined to a wheelchair after suffering a debilitating stroke two years ago. He has no family,just us. Advice?

His wife died of cancer last June leaving him alone,he has no family and few friends. My husband is his POA and I and I am his Health Care Proxy.
He is still living in his own home and I arrange all his healthcare appointments me hiring of staff to care for him.
The home health aide we have full time is acting off. I have found mouthwash and cough drops in the house which he does not use. She frequently goes out to her car. She is also short with him and and yells at him at times or carries on conversations with her husband on the phone in front of him talking about him. I count on her to feed him but recently found moldy food and expired cold cuts in the fridge. I spoke with her today bout respecting his boundaries and understanding he had a Traumatic brain injury and not engaging in unprofessional banter. She completely lost it started crying and freaking out. Shortly after I left she left too leaving two hours early. Is it time to part ways?