The court's opinion does not refer to Cal. Civil Code 1606, which reads, in its entirety, as follows: 

An existing legal obligation resting upon the promisor, or a moral obligation
originating in some benefit conferred upon the promisor, or prejudice suffered
by the promisee, is also a good consideration for a promise, to an extent
corresponding with the extent of the obligation, but no further or otherwise.

    On its face, this statute, enacted in 1872, would seem to support at least some recovery by Passante.  Do you see why?  But, consistent with a maxim of statutory construction that statutes "in derogation of the common law" be narrowly construed, early opinions of the California Supreme Court read the statute simply to preserve then existing common law exceptions to the rule that past consideration will not support a promise.  Those exceptions continue today, either by statute or at common law.  Under those exceptions, some promises to perform obligations that have become or could become unenforceable (e.g. because of discharge in bankruptcy or because of a statute of limitations) are enforceable without new consideration.  See R.2d Contracts 82, 83, 84, 85. 

     How would the Passante case have been decided had the following New York statute been applicable?

A promise in writing and signed by the promisor or his agent shall not be denied effect as a valid contractual obligation on the ground that consideration for the promise is past or executed, if the consideration is expressed in the writing and is proved to have been given or performed and would be a valid consideration but for the time when it was given or performed.  N.Y. General Obligations Law 5-1105.

     How would the Passante case have been decided under R.2d Contracts 86?