Probably not. Unless the person had been interdicted and declared legally incompeten, in which case the document and actions taken in reliance on its authority could be otherwise attacked, the individual is presumed to be competent. The question then is one of general tort negligence principles. Under Louisiana law such questions are resolved using a process referred to as "duty risk analysis". Without going through the whole analysis, the issue you have presented is a scope of duty question. In other words, did the nursing home have a duty to monitor and screen the activities of a patient not legally declared incompetent to prevent them from executing legal documents. Probably not based on my understanding of Louisiana tort law. The body of negligence cases in Louisiana does speak to the duty the nursing home has to prevent the demented or otherwise incompetent patient from wandering off and ending up harmed or dead, but not to the execution of documents. On the other hand, the nursing home personnel could be the best witnesses for you if you attack the power of attorney and actions taken in reliance on it. If they observed, and particularly if they charted the mental condition of the patient, then they could be of great assistance in a suit either for damages or to reverse the actions taken by the holder of the power of attorney. The foregoing is intended as legal information concerning the question asked, but is not intended as legal advice upon which the requesting party may rely in guiding their actions. Rather, the requesting party should consult an attorney for a personal consultation and advice for a full consideration of their situation and rendition of legal advice. Additionally, by providing this general information I am not accepting any representation of the requesting party and I am specifically declining to form an attorney-client relationship with the requesting party unless agreed to later after further consultation and agreement.