I was not present. My description came from that same friend who was present at Tahoe for some of those recording. We had a discussion at the time about where Maharishi could have obtained his meditation bija-mantras.
My friend and I knew something about mantra sourcing since we were both students of a remarkable European Buddhologist at collegetown. However, we only had Arthur Avaon and some other works on Tantric mantra. Thus we really couldn't determine more at the time. As far as other individuals are concerned, according to my friend, there was a Mr. Barrel Wight present in L.A. in that era. He looked sort of scarry yet didn't seem to be speaking much at the time. My friend assumed he was engaging in the practice of silence but maybe he was just a stoner. I did know someone who liked to shoot smack and then do tm on the down. If I remember correctly that person did have a special mantra - hum hum hu mm mm uh uh. However, I don't believe his name was Barrel Wight, so it's all a dream to me.