The point that makes it comprable to the Shiavo case is guardianship.
I'm assuming the wife was guardian. The kids disagreed. Greer ruled for the non guardian which does, indeed, give the appearance that his decisions in these cases would be more toward "pulling the plug" than abiding by the guardian's wishes. Is he pre-disposed in these type cases?
This and the Schiavo case are exact opposites in terms of situation, but parallel in principle. The issue with Terry Schiavo is that she didn't have a living will, but her guardian Michael Schiavo said that her wishes were clear, that she would want to die in this situation, and provided flimsy evidence to support his position. Greer bought that argument and sided with him over his nonguardian parents to pull the plug.
In this case there WAS a living will, but Clark's guardian Ping Clark said that her husband's wishes were clear that he wouldn't want to die in this situation, that there was reasonable hope of recovery, and provided evidence was no less compelling than Schiavo's for that conclusion. Yet, Greer sides with the nonguardian children in favor of pulling the plug.
To be consistent, Greer should have either went with the guardian both times, or basing the decision off of the living will (or lack of it). It does look like bias.