I had a GP Stik 40 and it failed in exactly the same place but at least I know why: I was diving too steeply and pulled up too suddenly with too much power on. I know, stupid.
I have seen a few Stik wings come off including the GP, Lan Yu, and a home built Stik. All of them after dives. They have very big wings and don't seem to like executing high G recovers from dives.
I miss my stik, it was one of the best flying aircraft I have ever owned and one of my future projects will be to build one from plans, already have the plans printed!