I’d say shooting him would be justified.
If I were in her shoes, and a strange man were in my bedroom, my first thought wouldn’t be “he wants to talk to me about my lawn”.
Um, nowadays, strange ANYONE, man or woman. Don’t underestimate women. You’ll be dead quick.
If I go to bed knowing for sure that I’m alone in the house, and I open my eyes and there’s somebody standing over my bed, something very ugly is going to happen, and it’s going to happen damn near instantaneously.
When it came to be known that it was some fat, officious low-level government prick that broke into my house to harass me for my lawn being a couple of inches longer than he liked, I would probably stop feeling bad about it.
I kind of like the idea of having my own video system -well concealed- so that there’s evidence that matches what I said happened, when the smoke clears.
You can bet he’ll be back with something else on his mind than the lawn. If not her bedroom door then her neighbor’s.
And it wouldn't matter if it were. He has no business in your house without your consent without a warrant, no matter what his purpose, absent exigent circumstances. Long grass does NOT qualify, no matter what the city or HOA may say.