1.) How long has the student trained for regardless of ability.
2.) How many students does your teacher have and does he need to pass bad students in order to make rent.
3.) How well liked is the student.
Some of you may disagree, but its simple economics and that's the shame of most organizations. Eventually everyone franchises themselves, even if they don't know it.
This is not always true, sometimes there are political considerations which means that students will never pass.