So what failed, this is a full flying stab, did the stab separate from the pivot pin?

Do you have any photos of the failed stab?

If the pin separated from the stab this has been an issue will other flying stabs from some of the other China built model manufacturers, in the past they have used soft balsa blocks to contain the pivot pin.

I have made a decision that from now on I will not trust a flying stab unless I investigate the internal construction either by getting an X-Ray or cutting the structure open...