I'm guessing there is a way from Software as I've seen tesco take some into store, they go into the back to the tech bit, do some stuff come back like 15 minutes later and its reset from a brick and such. There must be ways to reflash from software (not all tesco's did this, some said they had to send it away so I'm guessing its something that only specific engineers can do which are only in select locations).
My guess is maybe it's similar to how UEFI in laptops are, many laptops with UEFI are locked or severely limited in functionality, only way to get passed the limitations is by flashing the UEFI partition with a custom bootloader and BIOS. Obviously on laptops this is easy since Windows can directly communicate with the BIOS. So I'm guessing the first thing that we'd need to do for the Hudl2 is the boot/UEFI/BIOS, without somehow hacking that first we won't be able to do anything. But just my guess.
So it would take a lot of digging to find a way to access the UEFI to reflash it, I couldn't even find a "recovery menu" like many tablets do when you hold things like Power and Vol +.