Holy frak! That make absolutely perfect sense!
Death couldn't take the owner of the cloak until he had already passed it on to someone else. Why hasn't anyone ever picked up on this before?
Damn... What would have happened if Riddle had gotten his hands on the cloak?
Author's response
Nothing would have happened if Riddle got his hands on the cloak. Having it does not constitute ownership, as Dumbles said it would not work properly for him, even though he owned the Elder Wand.