Based on case below - who has the legal authority to make these decisions? (Canadian law)

What legal risks do the members of the care team face if they follow the patient's instructions? (Canada)

How can these legal risks be managed? (Canada)

CASE

An elderly patient, suffering from periodic episodes of dementia following a stroke, is intubated with a feeding tube. A Guardian was appointed for him after his wife refused to consent to a tracheotomy being performed on the patient. The patient's attending physician believes that, although the patient has suffered neurological damage, he is often oriented and can live indefinitely with breathing and nutritional support. There is a reasonable chance that he will breathe independently if taken off his respirator, although the attending physician is leaving it in place to be cautious. The care team agrees that so long as the patient's quality of life is stable, the ventilator and feeding tube should remain in place. The Guardian and the patient's wife support this plan. However, whenever the patient appears to be lucid he repeatedly asks to be "permitted to die with dignity," as is stated (in those words) on a treatment directive that is on his chart. If he can't be given medication that will hasten his death, he wishes to have his respirator disconnected and, if that doesn't work, he wishes to have his feeding tube removed.