After reading this story, I think it's pretty clear why Apple did what they did. In fact, I'm not surprised at all.
Apple is in my eyes a perfect example of why having the right corporate structure in place is everything. They are the most organized company I see around these days, and openly admit that their #1 priority is sales & new customers. With that said, why would they waste resources or reputation with a situation like this? The fact is that they're not responsible for your phone's whereabouts and for all they know, she could have been trying to hijack the phone from someone else. Okay, so she had the police call, yada yada, but I actually see it from their shoes & understand why they prefer not to get involved with such a situation. I actually think that from a corporate standpoint, they did the smartest thing that they could have done.
Apple even lets MobileMe users track their phone's location, remotely wipe it & lock it. Who's fault is it that she chose not to subscribe to that service?

With
11.3 million iPhones shipped
within the last QUARTER, how can you expect them to help 1 person get an iPhone back from a thief? Fact is, it's the local authorities responsibility. Now whether NYPD would give a %$^@ or not is a totally different story. If they got it back, I think some detective's kid would get an iPhone as a belated Christmas present over her getting it back.
In summary, Apple played by the book on this one & you can't blame a company for doing that, . . . ever.