Previously on Equestria Girls: The Rubicon · 5:45pm Jul 4th, 2016
First show's the scene with the Maximals and Cogsworth bantering as described in A Maximal Crusader.
"What Happened with Cogsworth?"
We see the past Cosgrove smash the hard drive, followed by the current Cogsworth gathering particles from the Ashley Valley air space.
"I wasn't one to take any chances. He had it coming."