It seems that a select bunch of Nokia Lumia 710 and Lumia 800 smartphones that run on the Windows Phone platform has shipped, carrying unlocked bootloaders on them so that those with a more adventurous spirit will be able to load custom ROMs on their respective handsets. This particular error was discovered by biktor_gj on XDA Developers, and it is most probably human error that this happened, in Nokia's perceived rush to release those two smartphones to the market.
Ubergizmo, Select Nokia Lumia 710 and 800 handsets came with unlocked bootloaders