I had an experience a couple of years ago that reminded me of Fravor's description of the tic-tac's ping-ponging motion.
I was up on a hill star-watching. A plane flew directly over me, at just a couple hundred feet above my altitude. However, before I could hear the engines, I got pretty excited, because from my vantage point, it looked like a light rapidly changing directions, left, right, up, down. I guess the small variations in its course seen from an angle straight ahead of it, made it look like an object that was abruptly changing directions by a more dramatic amount.
Could fravor's ping-ponging tic tac have been another plane flying almost directly toward him?