Factual error: After the doctor returns to her quarters and retrieves some papers, she is trapped on a table or a desk or something and she pulls out a wire that shocks and kills the shark. Isn't it convenient that the jolt ends for some reason right when the shark dies, even though the circuit would have stayed intact and she would have been shocked upon entering the water. (01:23:10)
Continuity mistake: When the parrot lands on the casserole you see a bottle and some other items floating around it. When it cuts none of the items can be seen around the casserole. (00:51:30)
Continuity mistake: When the shark jumps out of the water and grabs Russell Franklin, it slams him down with his body face-down in its mouth. A few seconds later, in the underwater shot, his body is suddenly face-up in its mouth.
Visible crew/equipment: As Carter is swimming in the cage under water there is a frontal view of him where you can see the shadow of the camera moving down in the right corner of the screen. (00:24:45)
Continuity mistake: When Preacher says "Leave that to the white folks, brother" to Franklin you can see that Preacher looks rather serious. When it cuts, he is instantly smiling. (00:19:20)
Continuity mistake: When we first meet Preacher and he is feeding "Bird" some cream off his finger, the amount of cream on his finger changes between shots. (00:17:05)
Continuity mistake: When Carter is swimming down to the hatch, just after the technician has been eaten, you can see that when there's a shot showing what he can see, there's a straight beam of light presumably from his torch as that's the only source it could come from. However, when the camera moves back to see Carter swimming through the water, you can see that the torch he is carrying is moving around violently as he is trying to swim to the hatch. There's no way Carter could have held that torch straight enough for it to produce such a straight beam of light, especially since he's busy trying to escape being eaten by a freakishly smart shark. (01:17:35)
Revealing mistake: Towards the end of the film after Carter is being dragged along by the shark, and shot by the priest, his wound does not bleed at all.
Continuity mistake: When Samuel L Jackson is talking to LL Cool J for the first time, LL Cool J's facial expression changes instantly. (00:19:15)
Continuity mistake: Throughout the film, people's clothes get drier/wetter instantly. Most noticeable after Whitlock is attacked and rescued by the helicopter - everyone gets soaked but inside are dry. (00:42:20)
Continuity mistake: At the start of the film when the man is trying to remove the licence plate from the sharks mouth you see a shot of him holding on to the fin on the huge shark from above the water. you can see the man is a good bit away from the mouth of the shark yet when we see the underwater shot he is just finger tips from the license plate. (00:09:20)
Continuity mistake: Look carefully at the licence plate when Blake removes it from the shark's mouth. It bends and flexes as though it's made out of rubber or even cardboard. Of course in the next scene when he throws it on the walkway, it's an ordinary licence plate. (00:09:30)
Continuity mistake: When Samuel L. Jackson is grabbed by the shark (CGI) blood splatters all over the place. In the next shot the place and the water are spotless.
Continuity mistake: When Preacher is cutting through the oven, between the shots from where he is, and the view from the section of oven above him, the damage is entirely different. (00:53:50)
Visible crew/equipment: When Preacher's bird flies off, you can see the shadow of someone at the far end of the corridor on the floor. Since no-one else is around, this has to be the trainers shadow to whom the bird flies. (00:43:10)
Visible crew/equipment: When Samuel L Jackson is talking to Carter about the diving mask, a light screen is reflected in his glasses. (00:15:10)
Character mistake: When a helicopter winch operator tries to get the gurney with injured Jim inside the helicopter, he doesn't have any gloves on. No wonder his hand gets injured when the cable breaks loose.
Continuity mistake: In the part where they are climbing up the ladder and there's fire on the roof, just after the shark attack Preacher comes and pulls them up with knotted clothes, then he pulls it in with them through the door. When they go back the knotted clothes are there again.
Continuity mistake: Carter puts a bandage on his right arm because of the blood. When he tries to shot the shark the bandage gets larger.
Continuity mistake: When the shark is attacking the oven which the preacher is in, the shark severely damages the oven's glass door. Later, when it cuts to a shot from outside while the shark is bashing against the door, only a few cracks are visible in the glass. (00:53:40)
Answer: They viewed her as a villain because it was her research that backfired and caused all of the chaos, even though none of it was intentional and it was a mistake. But audiences can be ruthless and unforgiving at times. However, the ending did feel like a cheap cop-out that created more plot holes. And many do feel she should have survived and completed her character arc. I don't know why they never offered the ending as a bonus feature on the DVD, but fans started a petition on the Change site calling for Warner to release the original ending. Thomas Jane is on board as well, as he's promoting it on his Instagram account. So that's probably the best way to get Warner's attention if you want to see the original ending.