So where do you imagine to find this entirely objective source of information that's never heard of Trump and has no opinion on him one way or the other?

The person's bias is irrelevant to the evidence presented. If a cop finds a black man with a smoking gun standing over a person with a bullet in their head, it doesn't matter if he's a card-carrying racist if he argues the man with the gun is probably the murderer.

Though I'd add it does matter because that guy's defense team will try to undermine the cop's credibility by saying he's biased and so any evidence he reports must lack credibility. Kinda like the story we're being fed about Steele.