Before permitting parol evidence of the surrounding circumstances culminating in a letter of agreement, Rip, C.J. noted (at para. 38):
Under the parole evidence rule when a contract is reduced to writing it cannot be varied, added to or subtracted by parole evidence or prior extrinsic matter in writing. However, an exception to the parole evidence rule permits the parties to lead evidence demonstrating that the written agreement is not the complete agreement; more precisely that it refers to any prior oral or written communication [citing inter alia General Motors of Canada at para. 27].