Correct me if I am wrong, but it seems to me that (Lieberman) delegation is quite a dangerous concept when applied to the most popular object oriented languages. You're effectively calling another object's methods and masquerading yourself as that object, or to put it another way you're exposing all of your privates and implementation details to another object. Hence it is much more dangerous, and potentially quite incorrect, than just forwarding.

The only safe way I can see this being done is by adding a reference to object A when calling/forwarding a method on object B. But that's just forwarding with extra data.

Maybe I haven't worked enough with fully dynamic languages, but I don't really see much or any benefit to doing 'Lieberman' delegation, over and above other options.