[UCANSEE2]

From the photos I saw, it looked like common R/C model controllers were used.

Or... the RC controllers were in the backpack to cover other things in case of a 'casual search' by security. Or they were there to keep the public from knowing just how simple this whole thing was.

[Dead Corpse]

There are pictures of fragments of the ICs and batteries taken at the scene.

Apply Occam’s razor here.