Yeah I was shocked the big blackout happened in the back-up! Amazing huge excellent issue. I thought it was cute that Bats dragging Joker down off the copter was from the ending of Batman 1989.
One thing fooled me; I thought the Red Hood Gang was building EMP bombs and were going to cause the blackout. I thought that was the point of the whole 'they're stealing random things to mask what they're really building' bit.