I did enjoy this book and it has been researched well in terms of the people. I think it does a good job of talking about some of the characters at RBS.
The book describes in great detail the investment bank, CDO's and acquisition of ABN Amro along with portraits of the people involved in these areas.
Then casually at the end of the book it is made clear that the majority of the losses were in property lending in the UK and Ireland. However up until that point there had been no mention of property lending or any of the people involved in that part of the business. I would have thought that the area of the business responsible for the largest losses should have been covered in some way. What happened? Who were the people involved?
Also in his conclusion he implies that HSBC was just as bad as HBOS and RBOS which is pretty unfair. Tax payers have not had to bail out HSBC. While the management of HSBC are not perfect they are in a different league to Fred Goodwin and company.
Overall, I think the flaw is that the author does not properly understand finance. I have also read "Hubris: How HBOS Wrecked the Best Bank in Britain" and "Anglo Republic: Inside the bank that broke Ireland" which in my view are better books because they properly explain what happened. After finishing Make It Happen I feel that I still don't completely understand what happened at RBS.