That's all very interesting stuff, but somehow I missed something: how was he able to verify the fake finger prints from the minister were usable and close enou

That's all very interesting stuff, but somehow I missed something: how was he able to verify the fake finger prints from the minister were usable and close enough to the real finger prints to fool a biometric device? I read the article twice and haven't spotted how he verified the hack worked in the case of the minister.