It does appear that different Authorities are introducing new questions at different rates, and that many Authorities are less critical than the UK CAA of new questions that are defective. In other words your chances of successfully appealing a defective question may be higher in the UK than elsewhere. In the UK it is normal for a number of papers to be remarked each month following appeals by schools or candidates so that, when a defective question is identified, anyone who got that question 'wrong' according to the marking scheme is credited, whether they appealed in person or not. This usually just leads to a new mark for those that passed, but in some cases can turn a 'fail' into a 'pass'. Where this process would lead to a 'fail' just being recorded as a 'fail' with a higher percentage the UK CAA do not adjust either adjust the marks or notify the affected students.