Theres lots of evidence -
http://www.afterlifeguild.org/Thott/FD.php
http://www.afterlifeguild.org/Thott/FDnerf.php
http://youngsdojo.tripod.com/Pulling.html
That was one google search with links from first page
First link mentions repeatedly FD'ing (dozen times) to separate a dragon from its guards
Second one mentions having at /q which was common when aggro refused to drop
Third one explains exactly the tactics required - tactics which would not need to exist if you could simply lose aggro by sneaking after FD