I my view, code complexity is best expressed in the size of it's syntax tree, with maybe an additional term for the number of unique nodes. The real mistake here is the assumption that local reductions in complexity make a meaningful difference to overall complexity. Small local decreases in complexity may guide you towards the local minimum of complexity, but will never substantially change the complexity of the code-base overall. All measurements of code complexity are essentially as good as asking "how much code do you have".
That is ultimately by problem with the article. It isn't a bad investigation but it cannot stand alone. I never review on function in isolation. It always needs to be in context of what calls it (and often what it calls).
