A very common ground of appeal is that the 'reasons for decision' are inadequate. Decisions (for orders, judgments and similar) should, with rare exceptions, be accompanied by adequate judge's or adjudicator's written reasons. In my opinion, this is a vexed area of law because of the court's refusal to establish firmly a principle that was urged 20 years ago in R v Sheppard (SCC, 2002):
[28] ... The simple underlying rule is that if, in the opinion of the appeal court, the deficiencies in the reasons prevent meaningful appellate review of the correctness of the decision, then an error of law has been committed.
Absence of such 'reasons' simply leaves one in ignorance of the basis for the ruling, what everyone involved should do legally and factually do different in future - and with a profound loss of trust in the legal system. Indeed without written reasons the common law can't exist, as it's 'reasons' - discussed amongst lawyers and subsequent judges - are it's very substance.
