Many of us have the misfortune to encounter the actions of regulators. Be they meddling in the energy market, the media, banking or more specific sectors of the economy, they have created a cult of pseudo-science around a framework of snivelling microeconomic jargon and third-rate models. Their organisations are staffed by theorists, and it is difficult to contemplate whether their competency is high given that their own models would suggest that they are being underpaid compared to the competence and over-inflated salaries of those they are expected to control. At best this makes them marginal, at worst prey animals in the world of legal and contractual carnivores employed by the organisations they are meant to be controlling.
The embezzling of the BHS pension fund would probably not have been prevented by a more effective regulatory framework, although there is the suspicion that if you play games of cat and mouse it is usually the mouse that gets eaten. The apparently shady deals, with an alleged venture capitalist who Green either claimed complete confidence in or total ignorance about, depending upon which version will best suit his narrative, might not have been prevented. However, a climate where moral choices are based around the practice of game theory spawns this kind of charlatanry.
John McDonnell is quite right in suggesting that someone such as Green should not regard their riches as immunity from scrutiny. To argue that an MP might have views that disqualify him from challenging the behaviours of a man who has clearly supplanted the late "Tiny" Rowland as the unacceptable face of capitalism is the act of contemptuous hubris that should send even the most ravening friend of capital into self-doubt. The behaviour of the self-styled wealth creators and their captive regulators is the likeliest catalyst for a lurch to the left than anything that could be organised by the left themselves.