Also, you're trivializing the challenges likely faced by the kind of venture. It's not always possible to find all bugs, unless you want to code in Ada and formally verify things with OCaml and are trying to fly a plane.
The problem could have been caused by a strange hardware defect, a rare bug in a library, etc.
Or competition, a disgruntled employee, etc. Just speculating but IMO it's a pretty big coincidence that it failed exactly when they did the IPO.
I read that to mean that this is the first time they've ever used their IPO-related code in production and it failed badly. So it sounds like it was the normal sort of bug, in their own code, and their own IPO directly triggered the bug.
It happened in less than a second.
You might also familiarize yourself with the Just World Fallacy: http://en.wikipedia.org/wiki/Just-world_hypothesis