If you're having this problem please do what ever it takes to get it corrected. A lot of guesses on this and other forums as to what causes this problem and there may well be more than one contributing factor.
I think the tolerances on the neck bearings (the fall away) may have something to do with it. My guess is that after putting miles on the bike (from the first thousand miles to many thousand miles later) that the bearings race seat down just a bit further, allowing more "slop" in the neck bearings. The dealership may tell you that the fall away test is within factory specs. However, I know of two members on this forum that had this problem and after taking it to several different dealerships, insisted that they tighten the neck just a tad bit more and the problem went away for both of them. In short, a "loose" factory spec may be just a tad to loose, in my humble opinion. Might want to consider the tighter side of that factory spec.
Take a look at this very unusual video.......