In theory, there's no difference between theory in practice; In practice, there is. ;]
OTOH, Here is a supposed example of an attacker circumventing TouchID iPhone-access controls: "The video shows in detail how CCC member "Starbug" managed to fool the Touch ID sensor of Apple's new iPhone 5s – using only a scanner, tracing paper, a pcb and wood glue." [1]
https://www.heise.de/video/artikel/iPhone-5s-Touch-ID-hack-i...