Dropped chain?

The only time I have ever dropped a chain while riding singlespeed was because I didn't have enough chain tension and that appears to have what happened while riding at Huntington on Monday. I had just hammered up the climb from Hopewell Road and heading up to the intersection with the white trail is when the chain dropped. I went a little further down the trail but I could tell it just wasn't right so I stopped to put more tension on it.

What this meant was the 20 Nm of force that I applied initially to the pitch bolts was inadequate which also leads me to believe that ovalization of the BB shell could indeed be the source of my problems. Everything seems to start out fine but after awhile it appears to go downhill quickly. After re-tightening the EBB pedaling was very quite but then a little later that hollow sounding, thwang, came back which sounds like there is still movement with the EBB.

As for the creaking sound, I no long think that is in the drive train, rather the head tube. I mad a video to capture the sound of what I am hearing. Disregard the higher pitch sound because I think that's my brake levers but the more hollower, longer sounding rattle that comes and goes reminds me too much of the sound aluminum would make if it where cracked and rubbing on something.