In The Invention of Science, David Wootton takes a whack at strawman Herbert Butterfield, as follows:
"In 1931 he had published The Whig Interpretation of History... Butterfield argued... it was not the historian's job to praise those people in the past whose values and opinions they agreed with and criticize those with whom they disagreed; only God had the right to sit in judgment" (p. 21)
"It should be obvious that he was not right about this: no one, I trust, would want to read an account of slavery written by someone incapable of passing judgment" (p. 21n).
This is a silly caricature of what Butterfield thought. Consider the following quotes from The Whig Interpretation of History:
"There can be no complaint against the historian who personally and privately has his preferences and antipathies..."
"If he deals in moral judgements at all he is trying to take upon himself a new dimension, and he is leaving that realm of historical explanation..."
So Butterfield quite explicitly says that, far from being "incapable of passing judgment," it is fine for historians to pass judgments as human beings. Butterfield personally is just as capable of disliking slavery as Wootton. Butterfield's point is that the historian's job is to determine what happened in the past, and condemning or praising various participants in historical events is no part of that job. This is not essentially different from arguing that, as a doctor, it is not the doctor's job to pass judgment on the sick who appear before him, but to cure them. Once Stalin or Gandhi is cured, the doctor is free to disparage the first and praise the latter. One may agree or disagree with this idea, but it is far from the nonsense Wootton puts in Butterfield's mouth.
And I have looked up every reference to "God" in Butterfield's book, and he simply does not say anything like "only God had the right to sit in judgment." What he does say is that historians have a tendency to mistake their personal judgements (with which, as we have seen, Butterfield had no problem) with "the judgements of history," and then to conflate history with God. If we want to sum up what Butterfield meant here accurately, we might say that, while everyone has the right to his or her own judgements, only God has the right to ultimate and infallible judgement, and practicing the craft of history does not make one God.