Yeesh. I hate UEFI - this should clearly be impossible with correctly-written firmware.
How did you go about creating the live USB image? The 12.04.x images don't have the right bits to make this work by just dding the image to a USB stick, but the usual failure mode is simply that the image is only bootable in legacy mode, not that it is available for UEFI booting but bricks the machine. Did you dd or otherwise raw-write the image to a USB stick, or did you use some program I don't know about to convert it?
If somebody has an unbricked but otherwise appropriate laptop and is willing to risk it, it would be worth trying out a recent 12.10 daily, because this is built in a somewhat different way which should allow for proper hybrid UEFI CD/USB booting. If this works, we could backport that to 12.04 without too much trouble.