上訴的根據一審期間的錯誤。上訴不是重新審。

Appeal after trial is that the appellant asks for corrections for mistakes made by the judge during trial.  Appeal is based on the trial transcript, you have to understand, anything outside the trial transcript is not relevant in appeal.  So your long history of how the prosecution progressed etc is not relevant.  

If you think judge made mistake before the trial, then you should have started a interlocutory appeal at that time, that appeal is based on the judge's mistake ruling for a particular motion.  Since your "relative"didn't start a interlocutory appeal, and the trial concluded, all you can appeal is the judge's mistake during the trial.  

Appeal court does not determine whether your "relative" is guilty or innocent.  Rather, the appeal court determine whether the judge made mistake.  If mistakes were made, and this is the best possible outcome, the appeal court could overturn the conviction and order a new trial.   There is no way for your relative to obtain innocence ruling from the appeal court.  

When a new trial is ordered, the prosecution could decide not to waste money and time and simply let your relative go free.  Or the prosecution will proceed and prepare for a new trial, and your relative will repeat it.