I would seriously doubt an experienced dancer ( lady ) would respond to being " led "..
Careful... Someone might take your quote out of context. By itself, it looks preposterous.
Still, even within the context of the lady's head position, I would expect an experienced partner to react to my positions appropriately. With respect to lead-and-follow, only some of what we do in ballroom is truly direct cause-and-effect. Everything else is response to cues based on logic and experience. True, I don't physically manipulate my partner's head, but through experience and training, she knows certain things I do with my body are indications that I want her to turn her head to the right (e.g. turning her to promenade position).
The same could be said of leading a heel turn, a rudolf ronde, a change of weight (or not) upon foot closure, etc... I never reach down and physically manipulate my partner's feet, arms, hands, etc... These are all things she learns to do as a natural reaction to certain cues. What makes us perceive this as "true" leading and following is the fact that the leads are logical and the responses natural. A very logical explanation can be given for each lead, e.g. why she should change weight as the feet close here, but not there. But it still remains that she is the one changing her own weight, as a logical response to some indication or another; she is not having her weight changed for her.
As for the Fallaway Reverse to Slip Pivot, I would never want a lady to open her head, and so I would never lead such a thing. Only the most experienced dancers can open their heads without at least a slight drifting of head weight towards the center of the position, and the slip pivot demands a complete pull of head weight to the left. And even with the best dancers, with the head weight stretched as far to the left as possible, opening the head during this movement as visually unappealing.
If you're looking for a good example of Fallaways with an open head, try searching for Drop Fallaway, Bounce Fallaway, or Three Fallaways. These can all be done with head open *or* closed (hopefully, as I mentioned, according to the man's lead). In any of these scenarios, my choice will be based on my partner's level of experience. If she can open her head while keeping the head weight reasonably well leftward, I prefer the look of the head open.
Regards,
Jonathan Atkinson
www.ballroomdancers.com