Continuity mistake: The crew arrived at the volcanic island in turmoil, and are talking with the local captain. The captain asks them to carry also some of the dead people, and they start asking him what the plan is, if there's one at all. The pass at the neck of the captain shows the side with the symbol in one shot, the blank one in the next. (00:25:10)
Continuity mistake: While Jax is held against the wall by two of the Furies it shows her bare feet held off the ground. As she moves across to Sinbad after he plunges the sword into the third Fury she is wearing flip-flops. (00:29:17 - 00:29:54)
Continuity mistake: When they are at Sarah's house, the boy's father tells her to go outside and ask Lucas to pull the van around back. When Sarah walks to talk to Lucas her long braided hair is tucked into her shirt and her arms are crossed. In the next shot when the camera comes back, her hair is on the outside of her shirt despite her arms still being crossed. (00:45:55)
Revealing mistake: When Gabby and Fin are hanging off the building in Las Vegas, you can see that Gabby isn't holding on to anything in some close-up shots. (00:11:47)
Revealing mistake: In the opening scenes, we see a very pregnant Draka reclining on a bed of animal hides as Durotan watches over her. In the extreme closeup, we see Draka twitch her lips, and her small tusks flex from side-to-side with her lips, instead of remaining firmly aligned with her jaw as they should.
Continuity mistake: The sun angle changes several times during the chase sequence when the dragon is on the flatbed truck.