Non-Domestic Rating (Deferred Payments) (England) Regulations 2009

The Minister is going very heavily on the fact that backdated revaluations happen quite frequently in the rating system, which is true. However, is there not a fundamental difference between a backdated revaluation, which results in a higher bill, and the backdated complete change in the system that applied to these businesses? In 2005, it was not that their rating obligation was revalued upwards but that the system changed that resulted in these huge increases, which were backdated for three years. Is there not a difference between those two things?