Corrected entry: In the first book, when the LEP officers stops the time, in theory no one can enter or leave until they abolish the magic circle. That's the plot's (and the characters') main problem, but later, the officers bring in Mulch Diggums and a troll, and that confirms anything and anyone can easily enter or leave. The problem with the time zone is non-existent, and the plot without the main conflict makes no sense.
Corrected entry: This mistake happens over the first book and the rest of the books. In Artemis Fowl 1, chapter 2, Artemis states that his motto is 'Know thine enemy'. This contradicts the rest of the books as the Fowl motto is quite deliberately pointed out as 'Aurum protests est'. The importance of the motto is shown as it is used as Artemis's password to his disc with his fairy memories in the Opal Deception. If it was not important, Butler would not have known that the password was definitely the Fowl motto.
Corrected entry: In Artemis Fowl (the very first book) Artemis decides to test his theory for escaping the time stop on his mother. Artemis' mother takes a sleeping pill, and when the time stop is initiated, she disappears. However, Artemis later states that when a time stop is initiated all persons will remain in the state of consciousness that they were in when the time stop began. Mrs. Fowl should not have disappeared; she should have maintained her state of sleep and remained in the manor.