Wow, my condolences man, I`m really sorry for your loss...
Thanks for sharing the video, it`s very instructive... I`m looking forward to seeing what was causing this, so keep us posted. Once I had a rod bearing failure in my SAAB because the pickup screen got obstructed, that was making a very similar clunking noise like this. If this is an IMS failure it`s surprising to me that you were able to restart the engine twice - I would assume the valves would get bent in each of the cylinders making it impossible to restart. Nevertheless, a complete dissassembly will tell you more about how to prevent this to happen again. I`d drain the oil and see what`s in there.