Sanyo might manufacture the same device, but label it under several different OMD labels,ie AT&T, Panasonic, Sharp, Verizon etc.
So the AT&T version might come with a 1 year AT&T provided “manufacturers warranty”, while the Verizon version might come with only a 90 day “manufacturers warranty”.
Panasonic might offer a two year “manufacturers warranty”.
The warranties are based on what the OMD company negotiated with the manufacturer, generally based on total volume or customer base.
The manufacturer is in Thailand or China.
Good luck contacting the manufacturer for warranty repair/replacement.
I'm going to presume “unlocking” the device will also void the dealers warranty.
That sounds like fun, for the consumer!