Other mistake: "Sally" the Great White Shark rammed Emma into a rock (or other hard object) underwater and Emma only got a small cut above her right elbow. It isn't clear how fast Sally was swimming, but Emma was rammed with force (and appeared to hit her back). A female Great White Shark weighs about 4,000 or 5,000 pounds, so Emma would be expected to suffer a major (not minor) injury under the circumstances. (00:05:24)
Other mistake: I don't think enough is known about the mating and birth habits of Great White Sharks to label this a factual or character mistake. Emma said, "Sharks return here each year to feed, mate, and give birth." I don't think sharks mate and give birth in the same location plus females give birth every 2-3 years. After mating (in deep water away from humans), the male and female go their separate ways and the female apparently gives birth close to the coast (shallow water) for the pups' protection. (00:03:36)