[alex_smart]

>You lose absolutely nothing. If you later want to handle the two cases differently, most IDEs allow you to inline the set_deadline method in a single key stroke.

Problem with unintentional coupling isn't that you can't undo it. It is that someday someone from some other team is going to change the method to add behaviour they need for their own use case that is different from your own and you won't even notice until there is a regression.

[kitkat_new]

in this case (which shouldn't happen because it requires that you merged things that don't belong together - see accidental duplication), at least the one changing the method has all information on his hands and doesn't have to keep a potentially complex graph of copied code in his mind.