Appeals courts are forbidden from considering matters of fact. When Judge Greer finds that there is no potential conflict between Michael's interest and Terri's and thus no need for a guardian ad litem, an appeals court is bound to accept him at his word unless he failed to consider all the evidence he should have; in that case, all the appeals court can do is order that he consider the evidence. If he still maintains there's no conflict of interest, the appeals court can do nothing.