The whole issue with any third party grader is that the grade they assign the note is someones opinion. When using an American grading company, they don't grade buy Charlton standard for the buyer to get a good evaluation on what to pay. I agree with Bob and Mmars that the grade given is correct, then reduce the value to the torn piece.
I have purchased notes from most of the standard grading companies and have errors in grading from all TPG's. NOT everyone is perfect. Best way for any buyer to not get taken, is to learn properly how to grade notes yourself (hard to do without having the note in your hands). Then you can make a judgement yourself if it is what you are willing to own for a price you like. If I am looking on line at a note I use conservative grading for sure since people can play around with tints and colour to make a note look better.
Wayne