A "terminating ruling" is one which stops the case, or in the prosecution's view, so damages the prosecution case that the effect would be the same. Adverse evidentiary rulings on prosecution evidence can be appealed for certain serious offences before the start of the defence case. These appeals are "interlocutory", in that they occur during the middle of the trial and stops the trial pending the outcome of the appeal. They differ in this respect from a defendant's appeal which can only be heard after conviction.
