It's OK if you play devil's advocate.
In my wife's case, she uses a horn ALL the time, like every day multiple times. (NOT in a "road rage" way)
She's a kind safety minded person and if there's any question some other driver may not see her, she gives little courtesy "toots" on the horn to avoid collisions.
So there's no question in her mind (or mine) that the horn worked when it was dropped off.
Understood, just a thought I had reading your post.