Plot hole: Timmy uses his heat vision, that he previously wished for, to win the race for his future dad. But it's revealed later in "Smarty Pants" that if you use a previous wish in a contest, it is magically taken away because it's cheating.
Continuity mistake: This mistake is found in the episode where Timmy wishes himself into the Crimson Chin's comic book after causing the Crimson Chin to become depressed. After defeating the Bronze Kneecap, the Crimson Chin are walking, and the Crimson Chin has no cape. When they appear before a large American flag, the Crimson Chin suddenly has a long, flowing, red cape flapping in the win. When they walk into the "letters to the editor" page, the Crimson Chin no longer has a cape.