The article itself says the theory isn't completely kooky. Quote: This is not as crazy as it sounds, and other engineers at SpaceX aside from Musk entertained the possibility, as some circumstantial evidence to support the notion of an outside actor existed. Most notably, the first rupture in the rocket occurred about 200 feet above the ground, on the side of the vehicle facing the southwest. In this direction, about one mile away, lay a building leased by SpaceX's main competitor in launch, United Launch Alliance. A separate video indicated a flash on the roof of this building, now known as the Spaceflight Processing Operations Center. The timing of this flash matched the interval it would take a projectile to travel from the building to the rocket.