Jim, the piston was not the cause. I believe that the circlip came out, or was never put in correctly, and the wrist pin slid out and then all hell broke loose.
When you install the circlips make sure they "snap" in place. When instaling mine I thought I had mine in all the way then I remembered selector's problem and made sure. Sure enough one of them needed just a little more of a push to get in good.
I have had zero problems and now have about 20 hours on the piston.
I think Erik (selector) had his forst piston installed at the Yammha shop and they fudged it up and then did not take the blame. :angry