Your definition of "bias" is far too narrow. And it is true that the same mind can produce a pattern without being biased, but that in and of itself does not mean that a pattern isn't actually biased.
A "news" story written from the point of view that a particular position is correct -- even if it does not state that position -- is a biased one.
These biases can manifest themselves in numerous non-overt ways, such as word choice, emphasis of certain facts over others, positioning of facts or data within a story, the possibilities go on and on. So no, they don't have to actually state a position as fact to treat it as fact.
It can be done much more subtly, too. For an example from CNN, during Clinton's war on Yugoslavia, Clinton was taking a lot of criticism for his contention that victory can be achieved through air power alone. On May 8, 1999, right in the middle of this tussle, when CNN ran its "today in history" blurb, they declined to mention that it was VE day, but they highlighted a battle in the Pacific from the same day in 1945, an insignificant battle of no particular importance to the war that no one but the staunchest of WWII buffs knew about, and noted that it was a battle in which the Japanese were driven from the island using air power alone. Did they mention Clinton's air war? Did they take a position on it? Overtly, no. But clearly, yes.
So no, "bias" is not nearly so narrow as you want to define it here.
