Our analysis of the Basic Situation was that Zack did commit theft by deception. (Our discussion of the Basic Situation is helpful in understanding this difference. If you have not already looked at that discussion, you may find doing so right now helpful.) In Variation One, however, no deception accompanied the transaction as it was occurring. It was only later that Zack realized the cashier's error. So where is the deception? There is none.
Theft Lawyers in New Jersey believe this distinction is crucial. Zack completed his purchase with no intention to deceive. At that moment, he was unaware that any misunderstanding even existed. The question, then, becomes whether New Jersey law imposed upon Zack some after-the-fact obligation to correct the cashier's error when Zack proceeded in good faith during the original purchase.
The answer is that no such after-the-fact obligation exists. Zack perhaps had a moral obligation to walk back and pay the difference. Failing that, and in the extremely unlikely event Chipotle's were to seek legal recourse against Zack, it might possibly prevail. That, however, would be a civil remedy. In the criminal context, Zack wins.
The previous paragraph used the phrase “extremely unlkely event.” Seeking recourse here would indeed be extremely unlikely. What makes it extremely unlikely is that the amount at issue is perhaps one or two dollars. Only a highly neurotic individual would spend the time, money, and make the needed emotional investment under such circumstances. And the very neuroticism that would cause some individual to seek legal recourse would cause that individual to make fatal errors in handling the case. The principle at issue here, however, is the same whether the amount in dispute in two dollars or two million dollars. In this latter situation, the purchaser's initial silence might indeed enable the seller to prevail but, again, only in the civil environment.