Hey Mike, this morning when I was out jogging, I saw god. She was african american.
If that really happened to you, then I believe you.
It just so happened that there were at least 8 witnesses, and the one that recounts the demonstration is a highly respected aikidoist.
If the man does not have a history of making up stories or creating illusions to "promote aikido," then I still see no reason not to believe him.
After a fight with a swordsman, O'Sensei walked out into a garden and felt he was enveloped in a golden light. As far as I know, there were no witnesses to this event, yet many aikidoists believe the story.
P.S. Do you have a history of making up stories?