I did a quick search to see if anyone had suggested this and didn't find anything so apologies if it has been.
Sometimes I head into the hospital just to be nice and revive people. Too often I have to click 5-10 people and try and revive them only to get the error about this person doesn't want you to revive them.
I suggest a visual aid somewhere by their name or by the revive button that indicates the status of their "allow revive" so people that do the revives for merits or to be nice don't waste their time on people with it turned off.