Your friend's statement, unlike the statement about Google, lacks inherent credibility.
Your friend's statement, for example, is far too general. Pretty much everything is biased in numerous ways. (That's different, of course, from saying that pretty much everything has a liberal filter.) Also, humans and the institutions they are part of (such as CNN) are especially prone to subconscious ideological bias, way more than computer algorithms are.
It is literally impossible to report news without any bias.
It is not at all impossible to produce a search algorithm without a liberal filter.