From the article: "The new platform has been designed to the highest levels of resilience with comprehensive back up, which includes dual processing at two sites and recovery from component failure within a second."
Hmm...where was the recovery? Did it mention anywhere why the recovery didn't occur? I'm guessing, though, that the company won't actively explain what failed or why.
Windows doesn't take 8 hours to reboot. I'm gonna guess that it was some data corruption or hardware failure that forced a rebuild of some large database node.
When I was in college (not that long ago) I had a COBOL class. I learned exactly one thing from that class: It is astonishingly...astonishingly...easy to fuck up financial apps. If you see a webpage where the margins are off, or the text doesn't align...that's bad. But in a financial app, the equivilent bug amounts to catastrophe.