Could it not be argued that the claimant has contributed to the OP as they failed to declare the change to their income in a timely manner. Most customer declarations state that they must declare all changes of circumstance within a calendar month of the change to avoid OPs or missing out on extra benefit.
Also, they should have received notification letters for the annual uprating of benefits in March/April 2016 and 2017 (and possibly 2015 depending on when Graeme's authority received the ATLAS record). I would've thought that these would show all incomes on the claim. They would at this point know that incomes that were no longer in payment but were being used in the calculation of the HB/CTR.
