I may not have as much experience as others, but I've never heard of this happening. Am i just naive?

Caph seems so relaxed about it.
It's because it already happened a couple of months ago and I was half expecting it to go again due to the metal becoming brittle.
Rest assured there is nothing fundamentally wrong with the Galileo and there is no design flaw.
It's much more mundane. I had a rear stand fitted to the bike that clamped between two moving parts of the rear suspension thus effectively locking out one side of it. This was exerting twist forces around the center of the downtube which it was simply not designed to handle. It took about a year and a half of this sustained abuse before the metal took enough damage to break.
It's really annoying that such a small thing can cause such a big problem. Hamant TIG welded it the last time it happened but obviously a new frame is now required.
I'll get it sorted out ...