I can't imagine any forensic psychiatrist making such a statement about a person who was seemingly functioning at work and with his friendships. This woman, whose training is never given, probably experienced negative transference and did not recognize it.
Dealing with troubling and troubled people requires mastery of your profession as well as common sense, patience and emotional stability.
I don't have the slightest idea whether he is the one mailing anthrax; however, unless he told his therapist that he had, the chain of evidence is only inferential.
"...As the Times, The BRAD BLOG, and many others have now noted, the case appears to hinge largely on the testimony of a social worker, Jean C. Duley, who had treated Ivins for a number of months in group therapy. As it turns out, however, Duley herself has a criminal history (as detailed by both Larisa Alexandrovna and Greenwald) and is no longer working at the Fredrick, MD, facility where Ivins was being treated, according to Bloomberg News..."
FWIW, high IQ VIPs have a tendency not receive state-of-the-art care. Part of the problem is if the IQ differential between therapist and patient is over 15 IQ points, communication problems are anticipated. Just like in a marriage, there is a subtle inability to really understand one another by virtue of thinking and reasoning on different bases.
Another part of the problem is very high IQ engineers, scientists and mathematicians and so forth are prone to be "hate to make mistakes types" who seem odd and eccentric to the average professional. Seemingly these individuals are hyper-rational on one hand but prey to the silliest worries and interests on the other. Their scrupulous and sensitive nature often makes the high IQ VIP prone to respond poorly to interpretations let alone criticism.
Like most in the bourgeois, these folks base their self system on how they look, how others see them and what they do for a living. Professional success is, then, the basis of much of their self-system. Threaten this, and you threaten their very identity.