Hi Ed:
I had the same thing happen about 2 years ago. Same experience, it left without a sound, when I gave it throttle a second or two later engine increased but bike and me did'nt. I hiked back and retrieved mine too. It was lying in a straight line directly over the path I had just traveled. A dealer had replaced mine and the half link had the locking part facing inward so I couldn't check to see if it was tight. I replaced it myself with the half link lock facing out so I can check it visually before I ride each day. No more chain brakes.
Neil and Buzzy the Bullet