Sorry for the issue, and glad to see you got it down relatively safely.
Just a thought here. Not sticking up for Goldwing, nor am I going to slam them. I'm struggling with the idea a plane could do that much damage to 1 wing in level flight at 3/4 throttle unless there was some aileron flutter involved at some point in time. Whether that occurred on a prior flight or in the flight just prior to you noticing something wasn't right prior to the wing folding or something. How/why that occurred would be at the top of my list of things to check out after seeing these pics.....
What caused the red flag to go up indicating it was time to land right now?