I can only guess at this stage of the game.
It sounds to me like the Power Company had long since upgraded their mains and transformer gear, but the equipment that was still in place at the shopping centre, had a lower PSCC limit than the NEW fault current level.
It failed to handle the new fault level and pretty much blew itself to bits.
BTW, this probably has very little to do with metering at all, as the meters that would have been installed would have been fed via CT's.
I would imagine what actually exploded, would have been the Main Circuit Breaker feeding the whole shopping centre, given that all of the shops lost power and that the blast was so large.
This is however only as I said, a guess.
Let's face it, these days if you're not young, you're old - Red Green