Tom, your comments about movie producers was dead on. Back in the 90's I was editing promos for a made for TV period movie called "Tad" (Lincoln's son) in which early in the film the famous removal of the Confederate flag in Arlington, Virginia incident occured. There was much discussion with the historical consultants, the producers and the studio big wigs about which Confederate flag to use. Unfortunately, truth lost that battle as they ended up using the Army of Tennessee battle flag that didn't even fly in Virginia and wasn't created until 3 years later! I pointed out the inaccuracy to the producer and he told me that the studio folks didn't think the viewers would even know what the first national CS flag would look like.
Cheers,
mike