>go ask your vegetarian friends how often they accidentally eat meat through no fault of their own

Huh? I've been a vegetarian for two decades, eat at restaurants often nowadays, and I've never had these sorts of issues. I mean, a small handful of times EVER someone made a mistake and served me meat (though once the mistake was mine) but that's quickly fixed. Never had issues where I ate half a real burger or anything like that.

I would never personally leave a one-star review for a mistake like this unless it was something that happened literally every time I went. I think leaving a one star review over a single mix-up is really petty. I also have the opinion that if you absolutely can't tolerate mistakes you should always be preparing your own food.