What do you think it is misdirection from?
First, I think it is misdirection because it leaps to a false conclusion regarding guardianship law, and does not make any effort whatesoever to factually express guardianship law. That is a good sign of misirection, although most people who engage in that are followers, i.e., they glom onto what they hear without researching it.
I think it is misdirection from the basic moral question of taking a legally innocent human life, regardless of its mental capacity.
I think it is also misdirection from a dysfunctional judiciary (but not quite as direct as the misdirection that advocates a focus to "we have to change the law," to the exclusion of other remedies.)
I think it is also misdirection form the current imbalance of power, in favor of the judiciary.
In this case, the guardianship canard neglects that from a legal standpoint, the guardian was obliged to carry out the patient's wishes. So, no matter who the guardian is, if the patient's wishes are wrongly found, then the patient's wishes will not be followed.