It seems that most of these problems would be solved by a time delay, like on safes at gas stations. You can disable the "Find my iPhone" service, and it will show as disabled, but it will actually stop working 48h or 72h later, so that there is a time window in which to catch criminals.

As always, the important thing here is for criminals to know this: even if they force you to unlock the phone, they are not off the hook.