My guess is
that the switches in question are managed by some MegaMouth Consulting business improvement partnership, who add value to the proposition by putting in PHBs all over the place to provide business continuity assurance within a integrated world-class best-of-breed process governance framework.
What will have happened is that PHB1 will have asked PHB2 to apply a scheduled upgrade, wiht a backout strategy in place.
PHB2 knows a bit about backing things out and in turn asks PHB3 to apply the upgrade and backout if necessary.
PHB3's knowledge of backing out is running for the pub toilet when he finds the gorgeous bird he's been chatting up is actually a transvestite. So it's something he prefers not to talk about in case his wife finds out.
So PHB3 tasks PHB4 with the upgrade, who in turns tells some downtrodden, overworked and untrained PFY to apply the upgrade. Do the core and redundant systems at the same time - delivery achieved quicker, time is money, young man.
So the PFY does his best, it all goes horribly wrong and it's taking days to fix. Guess who'll be fired for the disaster, though?