After seeing the con rod bent, it indicates that this was the result of the piston stopping sudde4nly and the flywheel inertia could not dissipate quickly. I have been told of such damage where cars have been driven through floods. I had a water leak in an engine years ago and the engine started and then when the throttle was opened, it dredged the excess fluid in the bottom of the crankcase through to the top. There was more than the combustion space, so it cracked my crankcase across the main bearing bores.
Conclusion. Always drain wells before starting after a rebuild or after leaving bike unused for above a week. It is a safety first proceedure and when you drain the wells, you can see if there is any water or debris.
So Erik, It was likely to be either a water leak or a total excess of fuel and oil. We are all very sorry that you have had such a devastating experience and send our best wishes for your eventual rebuild.
Roger
