I've always thought, myself, that differences in historical explanation invite a student to research and to think for herself, Patil.

It's similar to what your classmate Perks has been saying about the benefit of tutoring weaker students: Professor Binns's shortcomings are really an opportunity for you to refine what you know by testing the evidence against logic and justifications offered on all sides. This is surely how knowledge works. If you can marshal the arguments necessary to rebut Binns's assertions, your own knowledge and analytical skills will be the stronger.