"... It's forty-ten, forty-ten to Slytherin and Pucey has the Quaffle ..."
Harry could hear Luna's ludicrous lion hat roaring amidst the Gryffindor cheers and felt heartened; only thirty points in it, that was nothing, they could pull back easily. ....
Harry Potter and the Order of the Phoenix
The word 'in' confuses me here. I feel "only thirty points behind" makes more sense. Any thoughts?