Believe what you will, I admit it sounds far fetched, and maybe I'm just jaded by my own distrust of most if not all forms of government.
From a prohibitionist point of view, weed that is actually harmful goes miles in helping them achieve their goals. And really, what do they have to lose? It would be trivial for MI5 or whatever the DEA equivalent is over there to use proxy growers/distributors (people busted and looking for a way out of a hefty prison sentence) to flood the market with this shit without much risk to themselves. And the harm it does to the marijuana legalization movement is irreparable. I seem to remember that marijuana was to be made a different schedule (
from a class B to class C) shortly before this phenomena occurred, now it's being taken off the table by Brown because of the "
..involvement of serious crime in the cannabis trade.. and public health concerns"
From a marijuana market view, weed that makes people sick and has received world wide coverage for being harmful and adulterated will only hurt sales. Even bad weed sells well during dry spells, so why would they continue this process for as long as they have knowing full well that it has been exposed. It seems to me that anyone who has the know how to produce hundreds upon hundreds of pounds of marijuana without getting caught would understand basic economic concepts of supply and demand. As dry as it may get, the demand for poison marijuana will always remain low no matter the supply.
The U.S. government and the British government are intrinsically connected in most socio-economic policy as allies and purveyors of western culture. And I'm sure I don't need to tell you that all governments are capable of great and dastardly deeds in order to further their point of view or cause.
As for a premature accusation.. this isn't the New York Times, it's a pot forum. I'm a pot head with an opinion, sue me.