When Sam is reading a book in the loft, if you look closely when the dust-jacket comes away from the book, you'll see that she is really reading 'Harry Potter and the Deathly Hallows'.
When Spencer tells Freddie how to fence, he tells him that the aim of using the saber is to land a touch. While this is one way of scoring a point, it is far more common to slash at your opponent to gain the point.