Having this piece in hand really shows how bizarre Carnotaurus really was. Greg Paul pointed out how slender the lower jaws were despite a robust skull overall. Looking at the skull, the eyes were pointed out as small for a theropod too, which isn't helped much by the orbital bar. He further speculated that this may have been to reduce eye damage during butting matches with rival males. The deep snout might have had enhanced nasal organs.
I always wondered if the smaller eyes was an adaptation to particular lighting conditions; or if the weakly constructed skull meant that it was some sort of ambush predator that didn't tackle its prey head on?
As far as theropods go, I don't think the Carnotaurus necessarily had a weak skull, just probably not a super-strong bite. The head, to my untrained eyes, looks like it could certainly take a beating. It is relatively small, though. The forward-facing eyes, the long neck, the whole creature just seems very specialized, but we aren't sure what it was specialized to do, exactly. Also, we've got skin impressions of the beast, so that's awesome.
You're actually both correct. Dorsally, the skull was quite strong, but ventrally it simply wasn't very robust. There's a lot of heavy, layered calcification across the entire dorsal surface of the skull, similar to that seen in cresting the orbitals of older Tyrannosaurs. it was long considered by to have been an adaptation possibly with conspecific rivals, but more recent evidence points in a new and exciting direction.
The horns of Carnotaurus were corneous and had keratinous coverings, similar to extant bovids. In short, the horns of Carnotaurus would have continued growing with age and, as you can see in the SS piece, tend to begin to bow inwards over the years in a "U" shape. Also intriguing is that the muscular of Carnotaurus was definitely capable of shock-absorption, but when taking a lateral blow not only the epaxial musculature, but the entirety of the side musculature would have been involved. This means that with side-long blows with its horns, Carnotaurus would have been capable of dealing positively devastating damage to small prey animals, utilizing the strongest region of its skull and maximizing muscle use. Take all of these factors into account, and you quite likely have the first known carnivore to use its horns in order to obtain prey.
Also, for however weak the skull is ventrally, it makes up for its modest bite strength by having an
extremely kinetic skull. The premaxilla is capable of rotating upward, the maxilla outward, and the glut of sutures in the mandible allow for it to stretch and bow outwards like a python devouring a small mammal. Another factor taken into account is the origin and insertion points of the adductor muscles, which when analyzed demonstrate that Carnotaurus would have been capable of delivering fast bites as opposed to strong ones; quick, slashing bites, accumulating blood loss in prey items for an easier coup de grace.
Taking into account that the tibia and fibula lengths are quite long as compared to the femur, and we can determine that the Carnotaurus was built for sprinting at an accelerated pace, particularly for an animal its size. We can then piece together a fairly accurate model of how the Carnotaurus lived and hunted: running down small prey, outpacing them and goring them with its horns by vicious side-long glances; taking very quick, slashing bites; and finally devouring the small creatures whole as its skull expanded to accommodate the large meal.
Carnotaurus is an immensely fascinating animal, and I'm thrilled that SS has chosen this theropod in particular for the first maquette. Truly awe-inspiring.
I have put it in my curio cabinet, right next to the Rex vs Tric dio.
Gould also said, "Look in the mirror, and don't be tempted to equate transient domination with either intrinsic superiority or prospects for extended survival." However well I thought I was doing in her course, it was only halfway through the semester at the time, and the ball was firmly in her court; I had no illusions that she could erode my grade rather steadily if I fought her with dedication and vitriol. The other (science) courses for which I used that paper, were where my intended usage had its place. For her course I had to conform to her standards, which isn't asking a lot, being that she accepted my framework is suitable in a scientific context. We came to a fine accord, and it plainly boiled down to her criteria not being based on science but on coherence for a broad-spectrum audience, among other largely trivial aspects such as format and structure. Otherwise I have no doubt that back then she would probably have hung my ass out to dry in both her course and the honors program respectively. Monthly dinner and a movie night with the honors department faculty and a few other students was a much better alternative. 
