[william-newman]

Good advice would be "so be particularly careful to check whether their arguments are logically sound and properly documented;" the original advice to skip past the quality of arguments and data to "so take their conclusions with a healthy grain of salt" is bad advice. The ad hominem fallacy isn't just unsound in principle, it tends to be pretty useless in practice. It can look reasonable at the time if there's enough groupthink, but would anyone like to nominate some cases where with two or more generations of hindsight we can agree that ad hominem arguments were a better guide to truth than simply addressing the technical arguments? And it can be wrong no matter how impressively much circumstantial evidence suggests that there could easily be a political motive: see, e.g., http://en.wikipedia.org/wiki/Robert_Conquest .

[pierrefar]

I wasn't saying their conclusions are automatically wrong, but merely pointing out that this one requires a little bit more scrutiny given the obvious political leanings.

It's like reading a science paper that questions something with a ton of evidence behind it. You just have to ask "really?" of all their claims before accepting it or rejecting it.