1. Dear Dr. Peter, the first thing you should be aware of is that in the Law Library in Dublin, there is a motto that "where there is a will, there is a row". So, you need to realise that it is the natural course of events for someone to seek to find fault or challenge a will if they didn't get what that person views as their fair share. One of the ways in which a will is challenged is on the basis of lack of legal capacity. This issue is always decided on the basis of the medical evidence. So, in this situation, it will be a question decided on the basis of your medical evidence about the dementia or lack of it of the patient at the time the will was made. You will be called upon to give evidence and submit a medical opinion as to the state of mind of the testatrix at the time she made the will. Most likely, the matron will be called as well. However, the person challenging the will is also allowed to call evidence, including medical evidence in support of their contention that the patient or testatrix lacked legal capacity on the basis she had dementia when she made the will.
2. The applicant, or person challenging the lack of mental capacity will seek to argue that this temporary dementia was present on the occasion that the will was made thereby invalidating it. They will seek to have a medical expert who will disagree with your findings that there was mental capacity when the will was made. This medical expert will dispute your medical opinion that this dementia was only ever passing and was not present at the time then will was made. So, the case will be made that the dementia was either present on the occasion the will was made or else, was a more permanent situation that your opinion allowed for. Ultimately, the applicant will seek to make the case that your assessment was wrong. The judge will hear all the evidence and make a decision on what s/he hears. At this remove, it is difficult to say which outcome will result. However, usually, the medical attendant present when the will was made will be believed, as the applicant (or person challenging the will) bears the burden of proof in showing that your medical opinion was wrong. As the medical evidence of the applicant will be at one remove from what happened, it is hard for any doctor to be definitive about the situation. Normally, the disinterested evidence of the medical practitioner present when the will was made is believed. There must be clear evidence that the dementia was present when the will was made to strike down a will. Normally, there is never such evidence.
3. If there is any particular point you wish to have clarified, I will be happy to help further. Be aware that it is not possible for me to be definitive at this remove. That is why the judge hears all the evidence and decides then. Please Accept or Rate the answer as unless you do so your Expert will not receive payment from the website for answering your question.