You're assuming that whoever made the video performed it correctly from a manual and not from bad habits learned over time.
Instead of assuming some video is correct, how about text from the man who invented the method : http://books.google.com/books?id=KkB...epage&q&f=true
Or how about text from Hardee's Revised : http://archive.org/stream/rifleinfan...p/search/stack
"While the original battle [Gettysburg] may arguably be considered the epicenter of the history of the war, the GAC reenactment is not the epicenter of the hobby. To confuse or equate the two is unfortunate. - Bernard Biederman, 6 July 2012
"Authenticity conflicts occur when reenactors from one end of the spectrum attend events at the other end of the spectrum then try to impose their own standards instead of event standards."