OotP movie question

[harrysfannyc]

OK, if JKR is asked for advice about the screenplay why didn't she 
make sure that they mention the warning that Harry received from the 
M.O.M. in CoS, especially since this is mentioned in the new book. 
I know they haven't even thought of writing it yet but wouldn't it 
be something that should have been left in for the flow of the 
movies. This of course will come into play in PoA when Harry does 
magic on Aunt Marge & he worries about been expelled from Hogwarts. 
As a viewer (one who hasn't read the books) how are you to know what 
is going on & why Harry is worried about this.

Fan