Her husband legally cannot be her guardian. If those laws were followed, a new guardian would be able to call for a de novo trial on the basis that he was not present for the old one (best to have a formerly-uninvolved Schindler sibling become guardian for this). At that trial, without Michael sandbagging Terri's condition, it would be obvious that she was not PVS and there'd be no reason whatsoever to deny her reasonable care.
The FDLE was evidently on to Michael, see #505.