I recently wrote an article debunking the "Agent McKenna" theory. I found an audio recording of Terence McKenna clearly saying that he was actually 'deputized' by 'the mushroom,' and not the FBI. I also have a quote taken from Dennis McKenna's (Terence McKenna's brother) new book "Brotherhood of the Screaming Abyss" (A book about his and Terence's life together) that undoubtably explains how Terence easily resolved his legal problems with the FBI. You can read the debunking here: http://thepsychedelicist.blogspot.com/2013/09/my-response-to-jan-irvin-of-gnostic.html
Jan Irvin's (GnosticMedia) rebuttal to my debunking can be read on the Duncan Trussell Forums here for those interested: http://duncantrussell.com/forum/discussion/4080/jan-irvin-magic-mushrooms-a-tool-of-the-elite/p2