Did you take any before pictures of the firewall?
I wouldn't be surprised if there were some yellow mist with the black over it on the top of the vertical and roll over like in the picture of the Gold/black stripe Z I posted earlier.
If you study this, realize there are 2 different black paints here, the firewall black that has a fine gold mist over the top 1-2" of the firewall, by fine I mean a 5% coverage max. Then You have CODE 10 GLOSS Black stripe color leading to the edge on the cowl top. Looking at it knowing there are 3 different paints and where they are should help you and your painter understand what should be where. Who's on first?
if you look very close you can see the fine gold mist it looks almost like dust.
Yours probably had some yellow where the gold is here, blacks shot the same.