Corrected entry: How can Riddick possibly examine a skeleton and determine how the sensory system of a completely alien lifeform works enough to discover a binocular blind spot in a predator's vision? Bad enough that a predator wouldn't be able to see something directly in front of it (a massive hole in its hunting ability), but anyone not a trained biologist shouldn't be able to diagnose this from a few minutes with a skeleton.
Corrected entry: As Riddick is taking advantage of the raptor's blind spot, he is audibly stepping back and forth in a puddle. Even if the alien's sonar couldn't detect him, it would still be able to hear his footsteps. There's no possibility that it simply doesn't hear that noise, because the sound is similar in pitch to the aliens' sonar ping. With a sound like that the alien would be able to position him fairly accurately.
Corrected entry: In the scene where only the old man and the "girl" are left in the cave you see that there are only enough "light worms" to fill half of the second bottle, yet in the rest of the movie you can see that both bottles are full of "light worms."
Corrected entry: At the end of the movie, Riddick is in the ship, plugging in the power cells. Fluorescent lights flicker on and he doesn't react to it, even though he's not wearing his goggles that protect his light sensitive eyes.
Corrected entry: When the group is trying to get to the ship, it begins to rain. Where did the water come from? They are on a desert planet with little or no above ground water. Also, the planet's thin atmosphere would likely prevent such a downpour as it cannot hold enough water.
Corrected entry: The planet that eclipses the sun comes into position very fast. If the eclipse comes on fast, it would also go away equally as fast. Even with the width of the planet taken into account, it would be over in a matter of minutes or hours. Yet Fry explains that the planetary model they found shows how the darkness would last for a long time. Scientifically, this is not so. Also, the other sun is still out there. For a lasting darkness, both suns would have to be eclipsed.
Corrected entry: In the first half of the film a man look down a hole and shines a torch in it. A monster comes up and kills him but later on in the film the human flashlights can kill the aliens.
Corrected entry: While exploring the abandoned settlement, Fry goes inside one of the buildings and finds the room with the planet system model. It then cuts back to Imam and Johns walking up to the machine that draws water and you can see that Fry is with them. But then it cuts back to her looking at the models of the planets to show that she was in there the whole time. (00:23:25)
Corrected entry: When Riddick is talking Fry into leaving with him, Fry drops to her knees and Riddick helps her up. In the wide angle shot of Fry crawling up to the ship, you can see her left shoe fall off, but in the next few shots, her shoe is back on again. (01:37:45)
Corrected entry: As the group leaves for the settlement armed with the glow tubes, they are surrounded by a solid ring of raptors, at least 20. Just before Paris dies, his fire breath reveals 8-10 raptors around him alone. But when Riddick's night vision shows 4-5 raptors eating Paris, 2 more tussling away from the others, and a few flying around. What happened to the mass of raptors? Aren't they still attracted to the bleeding child?
Corrected entry: When Ali is discovered in the coring room, as soon as the imam opens the door, all the raptors fly out into the light, then down the shaft. The room they came from was dark and deep (therefore the opened door doesn't shed much light into it), and (as the rest of the movie shows) the raptors react to light and blood, not motion. They had no reason to fly from the safety of the dark room into the dangerous light.
Corrected entry: In the scene where Paris is blaming Jack for some noises in the ship, they see the silhouette of someone they think is Riddick. Zeke shoots him from behind and blood spurts all over Shazza in front of the man, but when he falls there's no blood or holes in his chest.
Corrected entry: When running from the canyon and in the rain, all of a sudden they are running and there is no rain and they are kicking up dust.