that is an interesting bit of an information in regard how the court and justice system worked.
The plot is actually quite obvious and it would failed if the King was actually capable of rational thought.
The proceeding probably reflect Ming Dynasty customs rather than those of the Shang Dynasty.
she does not even have a motive.
So the Concubine Huang is like: dude, she’s innocent
and the dumb king is like conflicted for a fraction of the second, but then Daki is like... you get the picture
yeah, the fact that she is the only one mentioned specifically only makes it even clearer that she’s being framed