Greer was acting as her proxy because he would not assign a guardian ad litem. That was another violation of the law. If he was acting as her proxy as he asserted, he was supposed to appear in D.C. Greer is a crafty politician, not a judge. Once that is understood, it's easier to see why he got things done.
He always gets things done - Terri's not the first.
He was acting as proxy for the health care decision explicitly pursuant to statute, as the request was made. Rather than a 'violation of law,' it was explicitly pursuant to law. If you don't like the law, you would apparently have the ability to do something about it [according to your screen name] other than simply mischaracterizing it. That decision has nothing to do with the three GAL's appointed.
He was proxy, pursuant to statute, for the decision before the court, not for each and every purpose.
I expect some screed in response, but factual accuracy is not partisan. I've heard this canard before, and it would be really helpful if folks would simply read Ch. 765 before offering all kinds of wild opinions about the scope of Greer's authority or responsibility.