So power failed at a UPS - wrong switch hit, or whatever. Which happpens, and UPSs fail anyway.
Thereafter, though: I know that bringing servers up all at once can lead to mayhem, but 'serious physical damage'? It also sounds very much as if failover to the other site was badly broken - obviously it was - but it's hard to make sense of the D Tel's narrative around that point.
I guess the main press attention will move on, and BA will be hoping that nobody will look too closely at whatever details are made public outside the company. But if the truth isn't a toxic mix of bad management, bad design, bad testing and bad ops, I'll eat a ZX Spectrum.