Beijing Cream has a summary of what vibes as the best account of Neil Heywood, whose murder precipitated the fall of the house of Bo:
Far from being a top-level fixer or spy, he was a failed businessman who found himself caught up in a situation he could not control. He then made a fatal miscalculation that led to his murder.
We pause here to note that the picture we get is not of a cunning baron who wielded actual influence, but a bumbling, desperate expat who found himself suddenly knocked off his pedestal occupied by China’s many “exalted laowai” — those who, arriving early to the scene, were often overestimated by the many people they encountered simply because of their foreignness.
I've still got business cards from a bunch of these guys who I met in Beijing in 1999. One chap who seemed to be running a business mystic/Tom Peters schtick had a consultancy called 'I will not complain'. The tragicomic thing is, If Heywood had gone to China ten years later he would have been a great hit on the rent a laowei circuit, with all that Harrovian smoothness. In fact he could have started an agency.
This is entirely consistent with him being an MI6 asset (NB, not an agent). However he did it, someone who lucked into extensive contact with a major Chinese political dynasty would have been of interest to SIS. Going around boasting about this may have contributed to his demise. The idea that he was a 'spy' crops up quite a bit in conversations within the Bo household around the time of his death.