Re: Penny wise pound foolish
What you are suggesting is that BA is lying to the public about the cause of the failure. Too much chance of being found it, I don't honestly think they would so blatantly lie to hide what happened.
I believe what is likely is that there actually was a power failure, which may or may not have been BA's fault (if its BAs responsibility to maintain the UPS, and they failed to do it, then it is their fault).
Having experienced a genuine power failure to the site, and some kind of failure in the UPS and generator system, I bet BA's remote off-shore India IT support team struggled to bring the systems and applications back.
So they're only telling 1/10th of the real story, enough to make everyone think they are not to blame, when in fact they probably are.