Sometimes my colleagues have told that they have driven a car for several miles without any possibility to recall what happened. They remember how they started the engine and then the next thing was that they find themselves at home in front of the garage door.
Most of the times this happened during a period of high stress level or tiredness.
I believe though, that this kind of state of mind, where your body is working properly but the mind is absent, can occur for the dancers too. Especially for the followers who can close the eyes, and just relax in the movement. It could be a kind of meditative state and I think that the followers, who have experienced of loosing the awareness of time during a tanda, have been somewhere there.