Plot hole: When the time stop is almost over, Root uses his "finger" to render Cudgeon unconscious. However, later in the book it is explained that if you lose your consciousness during the time stop you would immediately jump to the end. Cudgeon should have disappeared, and Foaly (or someone else) should have realized how Artemis planned to escape.
Plot hole: Artemis, Butler, and Juliet escape from the time stopped manor when they go to sleep. Artemis claims they escape the time stop by a change in consciousness. But earlier in the story, Butler and Holly get knocked out cold and don't disappear from the time stopped manor.