Plot hole: At the end of the episode when Tommy has change the witches into little statues, he's a werewolf. Then he runs to Stacey and changes back. However, in Hello Nasty it takes a Haiku from Merton to change Tommy back.
The Pleasantville Strangler - S1-E6
Revealing mistake: During the final fight, Merton gets strangled against the wall and hits the statue's face. The face moves less like rock and more like a mask.
Stalk Like An Egyptian - S1-E10
Revealing mistake: At the beginning when the Egyptian mummy puts the ring on his finger, the tip of the finger bends like a glove.
Deliberate mistake: At the very end, Tommy And Merton discover the video tape which contain pictures of Merton that had been film by her sister Beckie, but the movie was filmed and the time ''rewind'' because of the spell. So in reality, the movie was never filmed.
Answer: She left with her new boyfriend to go to a English college.