Stuff happens.
As a business traveler, I eat out a lot. A year of or so ago I found some foreign object in my food. I don’t remember what it was but it was also a supplier deal. I don’t expect the cook to inspect every bit of food.
I don’t ask but the restaurant did comp the meal.
Can’t tell from the photo, but looks like they ate a good bit of their meal (if not all of it) before complaining?
Ever see the movie “waiting”? There is a scene where the camera moves across the dining room during the dinner rush catching parts of various conversations.... one of them is the manager talking to a customer “Mam, I am not arguing your steak was overcooked, but did you have to eat the whole thing before you complained?”.....
I think of this every time I see someone complain about something that’s really a minor issue, especially at a lower end or family type restaurant.
I get it if you are paying a fortune for high end food, small details matter... that’s exactly WHY you are paying them so much for the food, but when you are at the bag and feed, and you make a mountain out of minor issues, I am laughing on the inside at you while you do it.