Ha yes ...
We do work our boat hard and enjoy the rough stuff, however we have only done about 180hrs in 2 years, which is not pushing it. We have not used the a-frame in an extreme way or one which is not expected (eg, tow by it etc). We just used the boat normally. Barnet inspected the weld, know why our welds caused an issue and had them rewelded. I dont believe they have had any other returns of this nature.
Anyway this is not an issue for us. Things like this demonstrate why the aftercare policy/reputation with your RIB manufacturer is an important consideration when you are making your mind up about your next RIB.