I guess the argument could be made that he never would have tripped and died if he never talked to this chatbot but that feels kind of hollow. They admit the man was cognitively impaired and they failed to supervise him appropriate for his cognitive impairment. there is no indication that they tried to limit his movement so he could have just as easily died on his way to get a package of Oreos at the store.
I get that we seek to blame things when tragedy befalls but the blame needs to be with the family not providing proper care for the individual.