On page 11 of the May 1929 edition of The Occult Digest, which you can read here, we have an account by Julia Seton M. D. She states this about an experience of applying anesthesia to a patient:
"Dr. Hunt bent his eyes upon me. I was almost spellbound with the intensity of his voice as he gave me a second command. I obeyed. Slowly but deftly I began steeping the patient’s senses. His pulse became almost imperceptible. I had reached a critical point—I looked at Dr. Hunt again, waiting for a signal to stop. He moved a little closer to the patient. Then suddenly something happened. To this day I cannot tell whether it was really the heat of the room, with the fumes of the ether acting upon my overwrought imagination, or if something actually took place. It might have been a complex-confusion in my own mind, but anyway, as I bent over the unconscious patient I saw a ball of soft hazy light gather around his head and face and from this a slender thread of light moved down and gathered into another flimsy ball of light just in the center of his body.
These two spots of misty light gleamed and seemed to act as the positive and negative ends of some occult electric battery. Then very abruptly from the center of this connecting thread another ray of light stretched out like a cord and lay over the sheet across the patient on the operating table. I followed it closely with my eyes and suddenly saw that it appeared to end in another body, standing very near the table.
I looked up and caught the fixed gaze of Dr. Hunt as he leaned forward breathlessly. I followed his gaze and we both saw distinctly the shadow body of the patient standing beside the operating table looking at his own body; then, lifting his eyes, he looked at the surgeons, next at Dr. Hunt and at last slowly looked directly into my own staring eyes, and at that moment there passed through me such a dizzy shock of electricity that I struggled frantically to keep my senses."
You might be inclined to dismiss the whole account as nonsense until you consider that during out-of-body experiences people often report seeing their body from a meter or two away from it, or seeing their body from a viewing perspective at the top of the ceiling. So it is far from unthinkable that an external observer might see something corresponding to such a person's out-of-body experience.
