286. The judge shall grant an appeal on the record if he is satisfied by the appellant that the judgment rendered in first instance is unreasonable, considering the evidence, that an error in law has been made or that justice has not been rendered.
Notwithstanding the foregoing, where the prosecutor appeals from a judgment of acquittal and where there has been an error in law, the judge may dismiss the appeal unless the prosecutor shows that, but for that error, the judgment would have been different.
Where the defendant appeals from a judgment of conviction or a judgment concluding that the defendant is mentally unfit to stand trial and where there has been an error in law, the judge may dismiss the appeal if the prosecutor shows that, notwithstanding that error, the judgment would have been the same.