Sec. 4. (a) An individual described in section 3 of this chapter may consent to health care unless, in the good faith opinion of the attending physician, the individual is incapable of making a decision regarding the proposed health care.
(b) A consent to health care under section 5, 6, or 7 of this chapter is not valid if:
(1) the health care provider has knowledge that the individual has indicated contrary instructions in regard to the proposed health care; and
(2) the individual has not been determined to be incapable of consenting to health care by:
(A) an order of a probate court under section 8 of this chapter; or
(B) the individual's attending physician under subsection (a).