> 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.
It's completely kooky, so kooky in fact, there's a (IMHO very funny) sketch about turning business competition into a gunfight: https://www.youtube.com/watch?v=mpC_hO15IoA. It's funny because the idea is so absurd.
United Launch Alliance has lawyers. Blowing up your competitor's rocket with a gun would be about the stupidest thing you could possibly do. The upside is low (single rocket launch ruined), the downside is massive (huge civil and criminal penalties). It also suffers from the typical conspiracy theory weakness: everyone involved would need to keep their mouths shut forever, and realistically, at some point someone's gonna have loose lips.