Causation of damages in contract cases, as in tort cases, requires that the damages be proximately caused by the defendant’s breach, and that their causal occurrence be at least be reasonably certain. A proximate cause of loss or damage is something that is a substantial factor in bringing about that loss or damage. U.S. Ecology, Inc. v. State of California (2005) 129 Cal.App.4th 887, 909.
In the context of breach of contract, it has been said that the term “substantial factor” has no precise definition, but is something that is more than a slight, trivial, negligible, or theoretical factor in producing a particular result. Haley v. Casa Del Rey Homeowners Assn. (2007) 153 Cal.App.4th 863, 871-872; see CACI 430, Causation – Substantial Factor, applicable to negligence actions.