Lifetime of LiveAPI callback function

Duggle ...'s icon

I've noticed it is possible to accumulate callbacks i.e it is possible to duplicate observers of a given object...(not useful).
Is it sufficient to delete an obsolete observer (LiveAPI() reference in a global array) by deleting the reference with myarray.pop()?
Is it even necessary to do this? Are the observers automatically cleaned up when the LiveAPI target no longer exists?