"...the incredible jaw-dropping stupidity of the idea that the whole thing might have been a government plot to assist it to pass repressive legislation "

Get used to it, Richard - there are thousands (millions?) of such anti-government idiots in the US of A and the number is growing daily. Gooble the "Oath Keepers" or take a walk thru the Southern Poverty Law Center site at www.splcenter.org

Its pretty likely that spokesmorons from the National Rifle Assassinatiion will shortly be suggesting the same thing.