Get another computer engineer, or at least tell him to get his facts straight
There is NOTHING in Win8 to stop you dual booting ..
He's talking about "Secure Boot" .. which isn't really (supposed to be) about stopping PC's booting something else like Linux.
Nor would installing an unsigned OS on a caddy overcome Secure Boot.
The spec for PC hardware being "Windows 8 Certified" is that the hardware must be UEFI with Secure Boot, but it's up to the manufacturers if they include an option to disable secure boot .. and as far as I can tell they all seem to be.
The spec for PC's with Win8 preinstalled is as above, but Secure boot MUST be enabled by default .. not a problem, disable it, or use a Linux that can deal with secure boot.
The spec for ARM devices to be sold with Win8 or AFAIK WinRT .. secure boot must NOT be able to be disabled .. but then who cares about Windows on ARM .. Android has that market sewn up
But most PC/motherboard manufacturers are including an option to disable Secure Boot .. in any case, most Linux distros have found ways to work with Secure Boot .. so it's not turning out to be the problem most people thought it would be.
or search for Secure Boot and Linux.
BTW, WUBI has nothing to do with Secure Boot .. WUBI installs Ubuntu INSIDE windows, kind of as an application (really it's a virtual drive), then uses the Windows bootloader to boot it.
See here's that confusion I talked about