On reflection, I was too harsh in my criticism, and "poor" is far too extreme. It was, after all, a very cleverly constructed puzzle, though I still see some aspects of it as problematic.
I think Deviant can probably relax. There is nothing in the preamble to suggest that the grid MUST be filled in a manner that conforms to the theme, and normally, essential requirements such as this are signalled in The Listener. If 4 is wrong in the submitted grid, then H and g are wrong in the puzzle's title.
The theme word is clear evidence that the theme has been understood.