(decedent executed a deed transferring several hundred acres to himself and his son as joint tenants with rights of survivorship during a period when his son was acting as the decedent’s medical power of attorney; after decedent’s death, the executor expended funds to investigate whether the son exercised undue influence; the investigation was insufficient; the son petitioned the court to order the estate to expend no further funds in its investigation, which the court granted; the executor appealed and further review was made in which the issue of fiduciary duties under a healthcare power of attorney were reviewed; the question was certified to the state appellate court; on the certified question, the court held under the facts there was no fiduciary duty created because no evidence existed that son accepted agency on healthcare power of attorney; in general fiduciary duty would be limited to scope of the power of attorney and not to matters outside the scope of health care decisions; by itself, the healthcare power of attorney does not create a presumption of undue influence).