The issue is not whether this doesn't happen; it seems to be about whether you can extrapolate from the few instances where gestures are necessary and where they are often used to consider that this is a reasonable explanation for how Lanfear could predict and slice Rands' weaves in the scene in the Stone. I think that is where there is a big leap in logic with a lot of assumptions loaded into it.

I bolded the areas in Verin's POV which indicate that Graendal turned without gesturing and showed that Verin could sense the woman channeling something, but could not see it. The only thing that makes sense is that Graendal was reversing the weaves she was attacking them with, and Verin's recognized that even though she couldn't see the weaves, the Forsaken was using the Power.



Yes, but this is not really the debate - I've established that while other groups or individual channelers may adopt gestures for certain weaves, that doesn't mean the weaves require the gesture. Nynaeve used to use her herbs to focus her Healing as a wilder, and she was trained in the Aes Sedai method of Healing, but we actually have a POV from her in TOM in which she mentions that Delving works better if hands were used, but it still worked - implying that the hands are not a requirement, but a focus for concentration.



Cyndane did not gesture with her hand - a ball of fire came from it.

Darius' explanation is that Lanfear would have seen Rand make a gesture and reacted to it, but A) she wouldn't have known which flow was used unless using a ward since a weave of Air often triggers invisible effects while that of Fire is visible and B) even if he gestured, if this was a common element in channeling, she'd have no way of knowing which weave he tried to use. The best explanation is that she had a ward up, sensed saidin being used and sliced his weave as soon as she detected it.



Well, that is incorrect in terms of lightning and fireballs - we already know that the Wise Ones and damane in general do not raise their hands for these weaves. We also know that there are different variations of the lightning weave - one that is aimed with the hands (possibly just focusing ambient electrical energy) and the variation that calls lightning from the sky. We've never seen any gesture used to call lightning from the air - we don't even see the channeler looking up to use this weave.

Further, my point was that while some groups or individual channelers use gestures, those gestures are not required.

And further, I raised this point before - it seems that raising a hand is an aid to concentration to aim combat weaves, but not a requirement. For example, when Nynaeve and Moghedien fought their first battle, Nynaeve thought that if any servant came in, all they would see would be two women glaring at each other across the room, even though their Shields and raw power were locked in a close fight. And when Asmodean fought Rand, both were throwing weaves at each other while running, but Asmodean wasn't gesturing at all - he was focused on running, implying that he wasn't gesturing but focusing his weaves using his eyesight.