Further, had Jobs decided to just let that incident go, it could encourage similar acts of espionage in the future as people would think they could get away with taking a device that's not theirs and selling it in the same manner.
On the other hand, had this customer decided to let it go and just return the iPhone and grab, for example, an Android device, there would be few consequences.
It's one thing to get frustrated about someone stealing/selling your items. It's very much another to feel a sense of entitlement for something you purchased which is returnable for a full refund and demand compensation or otherwise instead of just getting a refund.