Corrected entry: Snape accuses Harry of stealing Gillyweed from his personal stores because he found some Gillyweed missing from his personal stores. Later, Moody reveals that Neville Longbottom had provided Harry with Gillyweed because he had given him the book that led him straight to it. Surely, the book wouldn't have instructions on how to steal Gillyweed from Snape's personal stores, now would it?
Scrappy
5th Dec 2006
Correction: Snape does not accuse Harry of stealing Gillyweed from his stores. He accuses him of stealing ingredients to make Polyjuice Potion. It was in fact Moody who was stealing the ingredients to make Polyjuice Potion.
Scrappy