Dear Sincere Seeker,
You and KPuff have referred to being slain in the Spirit as “demonstrating surrender” or “an intentional depiction of an inner confession of death to self”. These would seem to indicate that one is conscious of doing the falling for a purpose. I don’t think that those who experience this are aware of demonstrating anything or depicting anything. They fall because it is natural as they feel the influence of the Holy Spirit. It is not a “thinking thing” or a sign for anyone but an observer who theologizes about it. For the one experiencing being “slain in the Spirit” he/she is simply doing what is “natural” when the Holy Spirit falls upon or refills him/her. It is personal, and the awareness of what it signifies is not what one thinks about at the time. A person feels something in this experience, regardless of what it means or signifies and receives it in his/her heart and is blessed by it and hopefully their life is somehow changed. Even if some of the experience seems slightly voluntary, it is still suggested by the Holy Spirit. The person is influenced by the Holy Spirit and is called to surrender and open up their life to what God may want to do in their life. Sometimes a person receives a healing or an understanding or some direction for their life while simi-conscious under the influence of the Holy Spirit. Some are wholey unconscious and will tell you later what God told them in that time, but some are only simi-conscious and may be aware that they are lying down and waiting before God during that time. It is a holy time for people when they are more suggestible and more easily able to experience God than when they are in their rational mind.