This is something that has weirded me out... if you hear of anybody's experience with the Orbs in the Amnesia series you hear people end up consistently describe an encounter with a guardian of some description. The only exceptions i can think of being the priests, kings etc. that agrippa mentions using or holding the orbs without any clear punishment for doing so.
What i'm trying to say is... even if the end result wasn't always the death of the thief, how come Mandus seemed to get away scot free? is the Machine a twisted manifestation of the Orb's guardian? did he simply move events along too fast for it to act considering the shadow that guarded daniel's orb was described as being incredibly lethargic with its actions? is Mandus's orb self aware and actively refusing the touch of it's "guardian"? there could be a completely logical explanation i'm missing here... but really it's absence irks me somewhat given every previous theft or removal of an orb was met with an eldritch other-thing hunting down the one who took it.