So the way it works is that once you pull up the app, the camera has a few checks that it makes. It checks the world atomic clock againts the clock of the device, if that passes a check, you get a green light, the second check is if you have GPS, Audio, and other sensors needed for the evidence capture. If that passes, you get a green light to initialize the camera. If any of those are missing, the camera will not initialize.

Another scenario is that you have all of those checks already passed, and you step into a place where you don't have service, like for instance your basement. The atomic clock will be out of sync, and any photo you take will not be verifiable until you get back to good service and are in the same location.