I do wish they provided the hardware specs too, though, as this reflects an incorrect UEFI platform implementation of MOR.
The guy unlocked the bitlocker, then restarted PC just before login screen appeared. He said that's when he had most success. What sense does it make to restart and start looking for key in memory, when bitlocker has been just unlocked.
You steal a laptop. You turn on the laptop. You reboot it into UEFI and steal the keys. This is bad for BitLocker. Ideally this is not possible because the MOR bit should cause the keys to be erased by the platform initialization before boot-from-USB is possible.
If I understand correctly, you need to start the PC, reboot just before the login screen appears, and boot to an USB application, which will copy the memory content.