In The Burlington Insurance Company v. NYC Transit Authority, et al., No. 2016-00096, the New York Court of Appeals issued a landmark decision with regard to the meaning of “caused, in whole or in part, by” in the additional insured context. In a split decision, the court rejected Burlington Insurance Company’s argument that the language implied a “negligence” standard, but held that coverage was provided to the additional insured only where the named insured’s acts or omissions were the proximate cause of the injury:
While we [the majority] agree with the dissent that interpreting the phrases differently does not compel the conclusion that the endorsement incorporates a negligence requirement, it does compel us to interpret ‘caused, in whole or in part’ to mean more than ‘but for’ causation. That interpretation, coupled with the endorsement’s application to acts or omissions that result in liability, supports our conclusion that proximate cause is required here.