Why didn't Snape turn Harry in?

[jadeey776]

No: HPFGUIDX 159154

I think you are right.  I think Snape wanted Harry to learn something
from the book, something he is going to need in his fight with
Voldemort.  It may be something he has already learnt or, more likely,
something he will learn in book 7.

I imagine Harry will go back for the book.  Seeing the vanishing
cabinet was important but I can't help feeling that he will get it
back during book 7.  The book was too vital and mentioned too many
times to not be a very important plot point.

jadeey776