The recurrent laryngeal nerve actually gives off several filaments to part of the cardiac plexus. On its way up it gives off fibres to the mucous membrane and muscular coating of the esophagus and similarly for the trachea, and then some pharyngeal filaments before reaching most of the laryngeal muscles (See Gray's Anatomy 1980).

During development the nerve elongates as the heart is forced down from the neck region into the thoracic cavity due to formation of structures in between. The RLN is surrounded by an unusual amount of connective tissue and actually supports the ductus arteriosis during development (the arterial duct that bypasses the baby's lungs during fetal development).

It has also been argued that the recurrent laryngeal nerve is actually less prone to damage by following the "groove" that it follows.

What is known is that the two sets of laryngeal nerves are responsible for innervating different vocal characteristics.
In effect, the proposed route of the design critics already exists. But the RLN exists anyway, providing, in the case of the larynx, a somewhat "redundant" backup, after performing other more obvious functions. As is well-known, the body is full of "redundant" backups, e.g. if a given artery is cut, blood can often still reach the intended destination through secondary backup routes.

Stimulation of the vagus nerve, off which the RLN branches, is known to lower heart rate and blood pressure. This can occur as a result of emotional stress. At this time, not enough is known about either the innervation of the larynx or the sympathetic interplay between the organs that the RLN innervates to be certain of any conclusions.

Multiple possibilities remain: (i) there is a function (possibly sympathetic) which is not yet understood, (ii) developmental considerations impose restrictions on possible trajectories, (iii) the nerve follows a very different route to that of the superior laryngeal nerve to provide additional protection not available in a more direct and developmentally viable route, (iv) it's bad design, (v) it's merely an artifact of unguided evolution, (vi) something we didn't think of.

What I was complaining about is that the article basically ignored all of this and presented a highly simplified argument. Even the first diagram gives the impression that the nerve comes down from the brain in a single sealed bundle like a pipe, loops around the aorta, then heads straight for the larynx without interruption. This is misleading at best. It is coincidentally the case that there is a great deal of variation in the course of the nerve from individual to individual. There are some hard constraints, and other things that are not constrained at all.

As with any complex interacting system, understanding the precise constraints in this particular biological feature is a challenging scientific problem. To simply assume "evolution did it" without careful investigation is moribund science.

The original argument of the article was made in published literature at least as early as 2001 (Intelligent Design Creationism and its Critics, Kelly C. Smith) and has been recycled very often since then. It is not the only example of supposed poor design in the body of mammals, some of which are now understood to have very important functions, which may be either viewed as evidence of good design or of elements that have been preserved by evolution for a reason.