How do you stage a coup of this size? Do they mean they influenced troops to participate? 2100+ is a lot of people. They couldn'tbe in the know. They are going to die or be severely punished. This isnt burning a government building down and using it for your benefit a la Hitler. Maybe they had knowledge like conspiracy theorists say about Pearl Harbor but staged seems a bit far. And they did lose control for a bit and it wasnt certain the populace was going to fight it. Hell the rest of the military seemed to be playing wait and see.
Though it is curious that none of the politicians were killed not even the kidnapped ones. Has to be one of these least destructive coups ever.
I agree that staging something like this seems impossible, but a small but influential and loyal group can maybe get others on board who are not in the know of a coup being staged.