Union Carbide Canada Inc. v. Bombardier Inc., 2014 SCC 35:
 The common law settlement privilege and confidentiality in the mediation context are often conflated. They do have a common purpose: facilitating out-of-court settlements. But as we saw above, confidentiality clauses in mediation agreements can also have different purposes. In most cases involving such clauses, the status of the common law settlement privilege will not arise, because the two protections generally serve the same purpose, namely to foster negotiations by encouraging parties to be honest and forthright in reaching a settlement without fear that the information they disclose will be used against them at a later date. However, as I mentioned above, settlement privilege and a confidentiality clause are not the same, and they may in some circumstances conflict. One is a rule of evidence, while the other is a binding agreement; they do not afford the same protection, nor are the consequences for breaching them necessarily the same.
 The differences between these protections may be muddled in a case like this one in which both of them could apply, but to different parts of the sequence of events. The parties met for the mediation session on April 27, 2011, the day after they had signed an agreement with a confidentiality clause. The clause in question applied to discussions that took place in the course of the mediation session and prohibited the disclosure of information about those discussions at any time in the future. A settlement offer was made at the mediation session, was kept open for 30 days after that date, and was discussed by the parties' lawyers after the session. Any additional information that came up in the course of these subsequent discussions falls outside the protection of the confidentiality clause — however, since it formed part of negotiations aimed at reaching a settlement, it is protected by settlement privilege. As regards the timing of the communications, the scope of settlement privilege is broader, because it is not limited to the duration of the mediation session.
 On the other hand, there are recognized exceptions to settlement privilege at common law that limit the scope of its protection, but such exceptions may be lacking in the case of a confidentiality clause. The question is whether an absolute confidentiality clause in a mediation agreement displaces the common law exception, thereby preventing parties from producing evidence of communications made in the mediation process in order to prove the terms of a settlement.
 There is indeed a delicate balance to be struck. The concerns articulated by commentators about the uncertainty of confidentiality clauses in mediation contracts are legitimate. Boulle and Kelly accurately identify the most important of these concerns:
The principle of sanctity of contract supports the maintenance of confidentiality where the parties have committed themselves to it. If, however, the confidentiality is too wide, it will sterilise too much evidence and seriously undermine the trial process. If the confidentiality is too narrow, it will discourage parties from entering mediation and from using their best endeavours to settle once there. A balance is required between supporting mediation, on one hand, and not freezing litigation or upholding illegality, on the other. [pp. 312-13]
 In my view, the inquiry in each case will begin with an interpretation of the contract. It must be asked whether the confidentiality clause actually conflicts with settlement privilege or with the recognized exceptions to that privilege. Where parties contract for greater confidentiality protection than is available at common law, the will of the parties should presumptively be upheld absent such concerns as fraud or illegality. I have discussed reasons why parties might desire greater confidentiality protection, and allowing parties to freely contract for such protection furthers the valuable public purpose of promoting settlement. As Professor Green states,
if a written confidentiality agreement exists, the parties are in a stronger position to argue that the court should exercise its discretion to grant a protective order assuring confidentiality because protecting the confidentiality of mediation statements furthers the expressed intentions of the parties as well as the public policy of encouraging extra-judicial settlements. [p. 22]
 But contracting out of the exception to settlement privilege that applies where a party seeks to prove the terms of a settlement is a different matter. As I mentioned above, a failure to apply this common law exception could frustrate the broader purpose of promoting settlements in that it might prevent parties from enforcing the terms of settlements they have negotiated. Thus, whereas contracting for broader protection than is afforded by the common law settlement privilege may further the overall purpose of that privilege in most circumstances, contracting out of the exceptions to the privilege might undermine that purpose. This may be what was behind the Court of Appeal's decision, as it largely favoured the exception to settlement privilege over the confidentiality clause.
 In my respectful opinion, the Court of Appeal did not devote adequate attention in its analysis to freedom of contract. It is open to contracting parties to create their own rules with respect to confidentiality that entirely displace the common law settlement privilege. This furthers both freedom of contract and the likelihood of settlement, two important public purposes. However, the mere fact of signing a mediation agreement that contains a confidentiality clause does not automatically displace the privilege and the exceptions to it. As I mentioned above, these protections do not have the same scope. For instance, settlement privilege applies to all communications that lead up to a settlement, even after a mediation session has concluded. It cannot be argued that parties who agree to confidentiality in respect of a mediation session thereby deprive themselves of the application of settlement privilege after the conclusion of the mediation session. The protection afforded by the privilege does not evaporate the moment the parties contract for confidentiality with respect to the mediation process, unless that is the contract's intended effect.