were qualified as experts for the purpose of this trial.1 As a
consequence, the trial proceeded as originally envisioned. It
would have been unjust to exclude the plaintiff’s expert
particularly since the reports had been exchanged in accordance with the agreed upon timetable and the parties and
experts had engaged in good faith attempts to narrow the
issues. Consequently, the evidence before the court was that
contained in the two volumes of joint record and the expert
evidence of the two accountants received orally and tested by
 I should observe that in addition to the viva voce evidence
of the experts, there are also affidavits from the controller of
Westerra and from the plaintiff’s business manager dealing with
book keeping and accounting. Much of the material reviewed by
the accountants involved information or records prepared by one
or other of these witnesses.
Interpretation of the Contract
 The proper interpretation of the contract is not an
accounting issue but is an issue to be determined by the court.
This will have significance for the accounting opinions because
in certain instances numbers have been calculated based on
assumptions about how the contract should be applied or items
may have been included in calculations that the contract when
interpreted by the court may exclude.
 Of relevance to this decision are the significant pronouncements on contractual interpretation contained in the
Supreme Court’s decisions in Sattva Capital Corp. v. Creston
Moly Corp.2 and Bhasin v. Hyrnew.3
 Although Sattva was actually a case concerning leave to
appeal from a commercial arbitration award, the court took the
opportunity to revisit the Canadian law of contractual interpre-
tation. Sattva stands for the following principles:
(a) Generally speaking, interpretation of a written contract is
a question of mixed fact and law in which the context and
purpose of the agreement will inform the interpretation.4
1 White Burgess Langille Inman v. Abbott and Haliburton Co., 
2 S.C.R. 182,  S.C.J. No. 23, 2015 SCC 23.
2  2 S.C.R. 633,  S.C.J. No. 53, 2014 SCC 53.
3  3 S.C.R. 494,  S.C.J. No. 71, 2014 SCC 71.
4 Sattva, supra, note 2, at para. 50. This is subject to the exception for standard
form contracts discussed by the Supreme Court in Ledcor Construction Ltd.