He's talking about the scientific definition of "theory". A theory in the scientific world, is a well substantiated explanation of some aspect of world. In lay mans terms a theory is accepted as fact in the scientific community. If he were to have said cell hypothesis, your outrage would have been well deserved.

You're so retarded that it hurts.

Yeah I don't think you got my point. Cells are a theory, thats why its called Cell theory. However, they are also an observed fact. Evolution is the same thing. Its both a theory and and a fact. This is because a scientific theory has a different meaning than a conceptual theory.