Shock, horror ?!
Speaking to Radio 4's Today programme McEwan said: 'I think that people, including executives at the bank, did not realise how big a change process we had to go through to get this bank back into shape. It has been a real shock how much time it is taking to turn it round'.
In the meantime, The Daily Telegraph reports that RBS has lost all the money invested in it by the UK taxpayer six years ago when the lender came close to collapse.
The bank has confirmed its total losses since its bailout have now drawn level with the £46bn pumped into it in 2008 in return for an 81% stake.
RBS made a loss last year of £8.2bn, its sixth consecutive annual loss, taking its cumulative losses to £46bn.
The scale of the losses means that all the capital provided by the taxpayer has now been used up dealing with the toxic legacy assets on the bank's balance sheet.