I've always felt that EY's wording ends up using words like "ethical" and "objective" in a different sense from most everyone else, which invariably confuses discussions more than it helps.

The sentence "murder is not ethical, even when committed by a pebblesorter" has two implicit assumptions.

First, that "ethical" means "human!ethical", which causes confusion because other people (not just me) would naively read the sentence as a claim of moral realism, which is a different thing.

And secondly, that "human!ethics" is a nontrivial set that contains such statements as "do not murder" - which is effectively a claim that all possible human cultures in the past or future (a hugely varied set!) share much the same ethics, or else that people who don't are "not human". I disagree with this empirical claim, and find the latter normative one pointless.