I don't deny the editor the right to hold views that are contrary to my own, and it is possible that in the fulness of time I'll admit that he was right. But, come on...he uses the study to introduce a fairly bombastic denunciation of Blair's "colonialism", "imperialism", "hate", etc. and announces at the end of his speech -- given at an antiwar rally where George Galloway was apparently also speaking -- that "We are the new resistance". This doesn't quite fit the image of the dispassionate lab-coated scientist who we'd turn to for an objective view of a complicated subject. I understand that his emotion might be the result of an honest belief that the war has unnecessarily killed a lot of people, but it still would be a lot more convincing (to me) if the study came from a journal that didn't appear to have such a passionate institutional commitment to the results that the study produced.
You can watch Dr. Richard Horton's speech at an anti-war demonstration in Manchester here. Horton wasn't one of the researchers, but he is ultimately responsible for the quality of the Lancet's stuff. Is it a problem that he is a passionate fellow, especially by standards applicable to Englishmen?
Similar questions come up about climate researchers, or conservation biologists and indeed any kind of scientists whose field intersects with a matter of public controversy. When we get to know them, it turns out that these people are not judicious, impartial types. They are fanatics. Should this lead us to distrust the science?
No. The "image of the dispassionate lab-coated scientist" is itself a product of 1950s-era Madison Avenue, better for selling soap than describing the dynamics of scientific discovery. Scientists are distinguished precisely by their ability to become passionate and blindly partisan about things -- like fruitfly pheromones and fluid dynamics -- that normal people find intensely boring. Republican and Democratic senators can have a drink after a party line vote; their staffers can date. Quantum loop gravity people, in contrast, despise string theorists with the kind of passion a DailyKos diarist would find unhinged.
Science doesn't work because it imagines that the participants can be neutral about their hypotheses. Their careers, their prospects of fame and quite possibly their ideological and existential commitments are bound up in them. Science works because there are clear methodological rules and because there is glory in successful criticism. Ideological biases are fine, especially when there are other people with the opposite ones.
One problem with the legal system is that it does seem to favour the kind of expert witness who is best at giving the appearance of being "above the fray." Judges don't want someone who shows their work -- they want someone whose demeanour makes them comfortable. There are understandable reasons for this, but it's a bit odd since the legal system is itself adversarial and devoted to the idea that truth will come from conflict of interest constrained by rules.
Update: There is a great thread at Cosmic Variance featuring a relatively accessible debate between string theorists and their enemies.
Update 2Via GNXP, I see that in pre-independence India, while Gandhi and Nehru's Congress Party largely attracted Brahmins with legal or journalistic training (something I had been aware of), the Hindu communalist RSS leadership, while also largely Brahmin in caste, were far more likely to have a scientific or technical training. Razib's discussion is quite interesting.