Continuity mistake: In the second book it says that Artemis' father's last memory was waving goodbye to his family but in one of the diary extracts, when Artemis is at the hospital with his father, his father talks about his time as a prisoner, which he shouldn't be able to remember.
Plot hole: Spiro's vault can only be opened by Spiro himself, but the guards change every hour and Spiro doesn't go to the vault every hour of his life to let the guards in, so how do they get in?