Well, I wouldn't say it's a 50/50 chance. You don't know if there is a flying teapot orbiting the sun or if there is an invisible pink unicorn or if the Flying Spaghetti Monster exists, but you wouldn't say the propability is 50/50.
Else I could ask: What is the propability that not god, but the Flying Spaghetti Monster arranged the energy? Or that Zeus did it? Or that no one did it? The propability for each possibility can't just be set 50%.