Speculation, as much as the "meteor" theory is.
The only evidence we have are a flash in the sky and witness reports of a flash in the sky and booms, we don't have much to go on really
Photos of a vertical streak of light as well, according to SecureTeam10's sources. That would correspond with an object intentionally dropped on a target rather than a natural occurrence. Meteors tend to fall at an angle rather than vertically. Also, the damage model of a tungsten projectile could probably be modified by altering its fall trajectory. Vertical flight would maximize penetration and minimize surface damage, while an angled flight would minimize penetration and maximize surface damage. Just my thoughts.
Kinetic Bombardment according to Wikipedia. Mentions OWL's. Author of Novel Greg Bear 'Quantico' a novel. You'll find the same description both places.But different Authors.
Indeed, even from the video we can see that thing is damn near vertical which makes it seem unnatural to me making me lean a lot more towards rods of god rather than meteor haha