Revealing mistake: When the crocodile attacks Sue from the water, it holds on to her canteen for two shots. You can see that the animal actually holds on to a prepared version of the canteen - it is cut in half, with its lower teeth inside to hold it more "comfortably" during the pull.
Continuity mistake: At the beginning when the helicopter lands, the helicopter's shadow goes out toward the rear right of it (from the pilot's perspective), but when Sue grabs her bags and walks to Walter, the shadow is now cast to the front right. Since Sue got out and was standing next to it, the helicopter did not move in the meantime. (00:03:15)
Suggested correction: You can tell by the shape of the snout and the ridges above the eyes that, although animatronic, it is meant to be a Marine Crocodile that is native to Australia. It doesn't resemble an American alligator, which doesn't possess those pronounced ridges. Also, freshwater crocodiles can be seen in the boat ride scene where Mick motions for Sue to lean up off the edge of the boat. They have the narrower, angular snout that you referenced.
The placement of the alligator's teeth when it closes its mouth shows that it is more like an alligator than a crocodile. In fact, the animatronic puppet is a bizarre mish-mash of physical characteristics of both crocodiles and alligators.