In Viner v. Sweet (2003) 30 Cal.4th 1232, the court explained, "An express concession by the other parties to the negotiation that they would have accepted other or additional terms is not necessary. And the plaintiff need not prove causation with absolute certainty. Rather, the plaintiff need only '"introduce evidence which affords a reasonable basis for the conclusion that it is more likely than not that the conduct of the defendant was a cause in fact of the result."'" (Id. at pp. 1242-1243.)