When two elements combine to cause damage, one being covered and the other not covered, issues arise regarding whether the loss is covered, and who bears the burden of proof to allocate causation between the covered cause and the excluded cause.
Courts have held that the insurance company will only be liable for that portion of the damage that was caused by a covered event. In the 1999, San Antonio Court of Appeals opinion, Wallis v. United Services Automobile Association, the court noted that a “straight Balandran analysis” would not apply in a situation involving multiple causes. Thus, as a practical matter, the practitioner must evaluate the claim underlying any lawsuit to determine if it involves allegations of damage allegedly attributable to multiple causes or simply one peril deemed to have caused the entire loss.
When covered and excluded perils combine to cause an injury, the Texas Supreme Court has held that the insured must present some evidence affording the jury a reasonable basis on which to allocate the damage. This is seen in the 1993 opinion, Lyons v. Millers Casualty Insurance opinion and in the 1965 opinion, Paulson v. Fire Insurance Exchange opinion.