Question: how do you know you did not fall asleep?
There is a level of deep trance that you may get into that has the awakener not working and you just come out when you like to. It is a state where suggestion don't really work anymore.
So you may be in that state.
You may also be just asleep.
Form the webpage linked: http://www.hypnotherapyempoweringyou.com/hs/hypnotic_state.html
Hypnotic State
Hypnosis works at different levels from a light trance to a very deep state. Issues of fear and grief need deep relaxation and surgery demands an even deeper trance state. I help the individual relax, sometimes using a progressive relaxation, taking them to a safe place of their choosing. Since they are motivated to work on an issue. I suggest that they will be as relaxed as necessary. The working hypnotic state may vary during the session and I am constantly aware and open to intuition and Spirit.
WAKING STATE: person responds to suggestions as when using EFT (Emotional Freedom Technique), and changing habits.
LIGHT STATE: body feels heavy and relaxed, used when regressing, or remembering forgotten information or lost objects.
DEEP STATE: somnambulistic state, used in stage shows (You will not bark like a dog unless you enjoy acting silly). Helpful for visiting past lives.
HYPNOTIC COMA: extremely deep state and person appears comatose, yet is aware (I used self-hypnosis during cataract surgery and aware of everything, but with no pain. When it was over I could go home immediately without recovery time waiting).
HYPNO SLEEP: the subconscious mind is aware even if the person snores and appears asleep (I tried it once and it took 15 minutes to recover).