Libby tells Hurley that she can't believe he doesn't remember her from the plane, because he stepped on her foot when he was getting on. She says she remembers him, the last person to get on the flight, arriving sweaty and wearing headphones, and then stepping on her foot. However, Libby was seated in the tail section, and thus Hurley, who was in the middle section, could not have passed her on his way to his seat. Additionally, in the flashback scene to Hurley catching the flight seen in Exodus: Part 2 (2005), it shows that while Hurley was the last person on the flight and he arrived sweaty, he did not put his headphones on until after he had already sat down.
The chain necklace that Mr. Eko takes from his brother in the episode ''The 23rd Psalm'' is a metal type. In this and the next episodes the chain necklace is totally different.
When Charlie comes out of the sea on the beach in the first shot, there are just Charlie's footprints around Aaron's cradle, but in the next shots there are lots of footprints.
In the cut between Charlie smashing the statue and reaching down for what was inside, the broken pieces of the statue have moved.
Eko tells Claire that John's baptism of Jesus cleansed Jesus of his sins. But Christianity (including Eko's Catholicism) holds that Jesus was sinless.
This clearly shows that he has no formal training as a priest, and only informally took over his brother's church. Due to this, his misunderstanding of the purpose of baptism, and other complicated topics is understandable. After his brother's death, and without formal training or a tutor, a lay individual such as Eko could mistake the sacrament of baptism as the only step to salvation.