[yongjik]

The whole point of the article is that there's no such thing like "functionally passive" and people will invariably twist themselves into knots if they actually try to give it a, let's say, functional definition.

You could simply say "You must be clear who did what" and it would be as good an advice as any, but people have to shove in "passive" into the advice, which serves no purpose and just makes things more confusing.