Ok which documentary are you referring to and what did he mislead people to believe?
I have seen like 3 of his films, not all of them, so I may be missing the obvious here.
Many of them are subtle...he will splice footage together to mislead people into thinking something specific occured.
In Bowling for Columbine he misleads the viewers on a sequence of events. The "cold dead hands speech" by Charlton Heston was portrayed to be in Denver 10 days after the Columbine killings when, in fact, it was a year later in Charlotte, North Carolina.
He does this a lot in his supposed documentaries....
The bottom line is Moore does present truthful things, but he intersperses it misleading information and downright lies........i
There are many examples of it.....and it isn't just a Dem vs Rep thing he had a hit piece on Dukakis that spliced together unrelated Bush Sr political ads claiming Dukakis allowed Willie Horton to get out of jail and kill again because of the furlough program......Willie Horton didn't get out of jail to murder anyone. He did commit crimes, but murder wasn't one. That part of the movie also tried to make it look like Republicans were going after black people in the ad. Unfortunately Moore had to splice two unrelated ads together to get the effect he wanted and added a caption that didn't exist in either original ad.
There are plenty of examples of this in his fakeumentaries.