Replying to Pivot/FKS Breaking

Long story short, I started using my narrower skis for groomers this week and my FKS heel broke. I was trying to get over on my edge to rail a turn and my ski popped off. I though I pre-released but it turned out my heel piece broke. Ski patrol wanted to take me down since it happened at the top and they told me there was a batch of bindings that had the wrong gauge aluminum about 5-6 years back. Does anyone know how this happened/ if this binding was affected by the bad aluminum? I really like pivot and would prefer not to switch to a different binding in the future.