Audi Alteram Partem
Ontario (Provincial Police) v. Mosher (Ont CA, 2015)
In this case the Court of Appeal, Watt JA writing, outlined the principles applicable to mootness and when an issue may be resolved despite it being moot:
The Governing PrinciplesOn the principle of audi alteram partem, Watt JA stated:
 The doctrine of mootness is an aspect of a general policy or practice that a court may decline to decide a case which raises a hypothetical or abstract question. This general principle applies when a court’s decision will not, in effect, resolve some controversy that affects or may affect the rights of the parties. As a general rule, courts decline to decide cases in which their decision will have no practical effect on the parties. This essential element – a lis inter partes – must exist not only when the proceeding commences, but also when the court is assigned the task of deciding it: Borowski v. Canada (Attorney General), 1989 CanLII 123 (SCC),  1 S.C.R. 342, at p. 353; Mental Health Centre Penetanguishene v. Ontario, 2010 ONCA 197 (CanLII), 260 O.A.C. 125, at para. 35.
 The doctrine of mootness is of general, but not unyielding, application. Sometimes it gives way: a court has and may exercise a discretion to depart from the doctrine: Borowski, at p. 353; Mental Health Centre, at para. 36.
 The approach taken by a court confronted with a claim of mootness involves two steps. The first step requires a determination whether the essential tangible and concrete dispute – the lis inter partes – has disappeared and the issues have become academic. If the response at this first step is affirmative, the second step requires the court to decide whether it should exercise its discretion to hear the case: Borowski, at p. 353; Mental Health Centre, at para. 36.
 The formulation of guidelines for the exercise of discretion in departing from the usual practice is informed by an examination of the rationalia underlying that practice. To the extent that a particular foundation for the practice is either absent or its presence tenuous, the reasons for adherence to the practice disappear or diminish. An examination of the authorities does not yield a neat set of criteria: Borowski, at p. 358.
 Three basic rationalia underpin the mootness doctrine:
i. that a court’s competence to resolve legal disputes is rooted in the adversary system that helps guarantee that issues are well and fully argued by parties who have a stake in the outcome;
ii. the concern for judicial economy; and
iii. the need for the court to demonstrate an awareness of its proper law-making function and the limits of that function so as to avoid intrusions into the role of the legislative branch: Borowski, at pp. 358-62.
 The first rationale may be satisfied where the live controversy has ceased but the essential adversarial relationship nevertheless prevails. Collateral consequences may provide the necessary adversarial context: Borowski, at pp. 358-9.
 The second rationale – the concern for judicial economy – may be met in cases which are at once moot but of a recurring nature and brief duration. A flexible application of the mootness doctrine ensures that important questions, which might independently evade review, are heard and decided by the court: Borowski, at p. 360.
 A somewhat more amorphous basis to justify the deployment of limited judicial resources arises in cases that involve issues of public importance of which a resolution is in the public interest. The economies of judicial involvement are balanced against the social cost of continued legal uncertainty: Borowski, at p. 361.
 In exercising its discretion to hear and determine an appeal that is moot, a court should consider the extent to which each of the three distinct rationalia for the mootness doctrine is present. The process is not mechanical. The principles may point in opposite directions. The absence of a third may overbear the presence of one or two. And vice versa: Borowski, at p. 363.
 Two brief points about the audi alteram partem principle are adequate to mark out the boundaries of the principle.
 The principle is an amalgam of two components. Each is a right accorded to a party in a proceeding.
 First, a right of audience. Said in another way, the right to be heard by the decision-maker. This right compels the decision-maker to allow the party to be heard so that the party has the opportunity to present his or her point of view: Supermarchés Jean Labrecque Inc. v. Flamand, 1987 CanLII 19 (SCC),  2 S.C.R. 219, at pp. 234-35.
 Second, and this arises out of the right to be heard, notice of the hearing sufficient in time and substance to enable the party to present his or her case on the issues to be decided: Telecommunications Workers Union v. Canada (Radio-Television and Telecommunications Commission), 1995 CanLII 102 (SCC),  2 S.C.R. 781, at para. 29; Supermarchés Jean Labrecque, at p. 235.