I probably was in some of those FWs. It is a combination of trying to practice WildThing's reversal technique with the huge roll rate of the FW. When the reversal technique was executed improperly (snap roll instead of barrel roll), you probably saw the phenomenon described by some of the posts above. Of course, once controls are damaged, then the uncontrolled rolling is more likely as well.
It works better in a maneuverable plane like the spit, but I am trying to get away from spits. At least the FW pilot can always ensure his roll is ahead of the opponent's. It think it's good for the game when each type of plane has certain maneuvers it can use to be effective in a fite.
Remember, in general, overshooting an opponent is bad, both in the game and in real life.