By the way, I don't mean to imply that only Michael Moore's works have lots of errors. One thing the blogosphere has done well is to fact check everything. And the dismaying thing is that they've found errors and lots of them in virtually everything, left, right and center. We've basically been continuously lied to by everybody for the last several decades.
One quick example that borders on absurdity. Michael Bellesile's Arming America was considered a brilliant and stunning work, showing that gun ownership in early America was actually quite rare. This had two important policy implications: (1) it would be unlikely that gun ownership would have been considered an individual right and (2) homicide rates were very low when gun ownership was low. Bellesiles won the prestigious Bancroft Prize for his work and his book has been cited as evidence in federal court cases and has had a significant effect on gun policy (pro gun control).
Only one minor problem. He fabricated the data. Because he fabricated the data and misrepresented a few other things, he was forced to resign from Emory University and the Bancroft Prize was taken away from him.
Not to be outdone by a pro gun control fraudulent scholar, John Lott, an anti gun control fraudulent scholar wrote More Guns, Less Crime. The main thesis is described by the title. An incredible concept that more guns could lead to less crime. Turns out that it is not only incredible, but not credible. He cooked the numbers.
Won't anybody tell the truth?