Corrected entry: After Hades tells Percy "give me the bolt or lose your mother forever" after the smoke clears, Percy drops the shield and runs to his mother. As they hug there is a cable and hook attached to Percy's mom.
Corrected entry: While fighting the Hydra in the Parthenon, Percy, with Luke's open shield on his arm, runs to hide behind the statue of Athena. He then stumbles and knocks the shield off his arm, sending it flying. However, he is never seen picking it up, nor did any of the kids have it when they raced to the door to leave the Parthenon. Percy just suddenly has it later in the movie.
Correction: After Grover petrified the Hydra, Percy could have picked it up offscreen before leaving.
Corrected entry: When Percy, Annabeth and Grover get in the prize car to get out of the Lotus Casino, there are blinking lights on the border of the windshield. But when they get to the Hollywood entrance of Tartarus, there are no more blinking lights.
Correction: The flashing lights are only a reflection from casino lights. They are not bordering the windshield.
Corrected entry: When Percy is fighting the Minotaur, it charges at him and gets its horn stuck. Just after this you can hear Grover asking Percy if he's OK. But he doesn't say "Are you OK, Percy?!" He says, "Are you OK, Malone?!"
Correction: He says no such thing. What he actually says is "Percy, behind you!"
Corrected entry: When the trio are in the Lotus Casino and Percy sees the pearl first, it is on number 15 on the wheel. But later when they are leaving and Percy takes it, it is on number 33. (01:18:35)
Correction: It's an active roulette table where people are playing. Plenty of time has passed, so the last time the pearl landed, it was on a different number.
Corrected entry: In the seen where Persephone stops the hell hounds from attacking Percy, Annabeth and Grover, she should not be there if the summer solstice was coming. She would be with her mother, Demeter, during spring and summer. (01:25:35)
Correction: She's not forced to leave in the summer, merely free to leave. With a possible war brewing, she can easily choose to stay where she is safe. If you continue reading the books, her mother even eventually joins her for safety reasons.
Corrected entry: In the scene where Percy and his friends are fighting the Hydra, Percy begins to wildly swing his sword to cut of their heads. At one point, he slices off the middle head which breathes fire, and it grows back. This is incorrect as the middle fire breathing head cannot be chopped off.
Correction: According to who? The movie takes some liberties with established myth.
Corrected entry: When Medusa first notices Percy she puts her glasses on the crazy lady's statue, but when they are later seen with the head she has glasses on.
Correction: Well yeah, one of them put the glasses on the head to make it safer to carry around.
Corrected entry: When Percy, Grover, and Annabeth go to meet Hades, they find his wife Persephone with him. This is impossible, as Persephone only lives in the Underworld during the winter seasons and the movie is repeatedly proved to take place during the summer. In Greek mythology and The Lightning Thief, the seasons are caused because her mother, Demeter, is sad that she is away from her daughter and causes the crops to wither.
Correction: 1 - this is a modern interpretation of Greek Mythology, there are several departures from the classical Greek myths. 2 - it's always winter somewhere. The ancient Greeks wrote all mythology centered around their own culture and immediate surroundings. Through the centuries Persephone may have left Greece and settled somewhere in the southern hemisphere.
Corrected entry: When the trio is in Hades' palace, one of Persephone's necklaces is a cross. The cross symbolizes a monotheistic religion, so it makes no sense for Persephone to wear one, because she is a goddess.
Correction: It's not a cross, it's a dragonfly. With its wings out, it could appear as a lowercase t or cross. It should be noted there's a species of dragonfly called Persephone's darner.
Correction: What you think was a cable is actually a sword in Percy's right hand.