He is being way too hard on himself.

Teachers have a difficult job for a multitude of reasons, one of which is that they are viewed as an extension of their students. If their students don’t care and do a bad job on their work, that must mean their teacher doesn’t care and does a bad job on hers, right? Wrong. You could put the best teacher in the world in a classroom of lazy, disrespectful students, and she couldn’t get them to be the best that they can be. She could try her best, but most teachers are not like the teacher in Freedom Writers. 

Because parents and administrators alike see students as an extension of their teachers, they view students’ failures as their teachers’ failures. It’s hard for them to accept that teachers can’t totally control how well their students do on a standardized test, no matter how well they prepare them. As a teacher, it’s not advisable to be a perfectionist with your students. If you get angry at every little mistake and internalize it as your own, you’re going to make your students afraid to fail at anything, and therefore, they will be afraid to try. 

The teacher in this story is a first-year teacher, and his worldview definitely reflects his lack of experience with the profession.