I saw heaps of 4pcs break in the 90's down there (being a HAZ and before post-welding heat treating) and likewise I've not witnessed it personally in the modern 2pc era, but I have seen a couple cases of it in the scene in the last 5 years. Certainly not enough to infer an epidemic, hell not even enough to rule out freak occurrence :0
Good to see you BTW, how goes the bursitis? I ended up getting it in my shoulder but after a few cycles of cortisone injections it came good