The National Association of Head Teachers says that increased online marking of A-level papers could be linked to rising numbers of inaccurate exam grades.
Of course, it isn't. The increased incidence of detection of inaccurate exam grades is due to the fact that more students are appealing against the announced grade.
There is no penalty for making an appeal, (other than an insignificant administrative charge), so game theory says that unless you are awarded an A*, you're stupid if you don't appeal. Exactly the same process is happening in higher education where the incidence of online marking has not changed significantly.
Students and accreditation bodies are now engaged in prisoner's dilemma where there can only be one outcome.