It seems vastly more likely to me that someone "arranged" to "lose" a phone ahead of time, to get it to Gizmodo with some kind of plausible deniability.

Presumably also there are uniquely identifying IDs in the phone (IMEI, but for a dev phone maybe that is in flash), or just a limited number of these phones, so Apple can do inventory and find out who lost the device. At that point, extensive interviewing to make sure the loss was actually a loss.