Cognitive Bias × Dreyfus model (1980)
As part of developing skill, experts come up with their own rules. They are based on their concrete experience and thus are somewhat arbitrary.
Experts often confuse other experts with novices solely on the basis of these arbitrary rules. i.e., a novice following their rules may be judged expert. And vice-versa—experts using their own judgment and intuition (and not following rules of other expert), might be judged as novice.