What exactly is a 'vegetarian mistake'?
Um. I'm not really following? :D
Oh, one of the options was, "Det var ett vegetariskt misstag." haha.
Oh. Well I've exprerienced one, when we were a couple of vegetarians being served chicken... :p
I think, this option is funnier:"Ni var ett stort misstag."
There are many people, I imagine, who would answer that way when being told they did something wrong. :D
Would fel work here instead of misstag?
Grammatically, without a doubt, but it would mean "error" rather than "mistake".
Tack! So misstag is more of a wrong decision while fel is for instance when something is grammatically wrong? I'm asking since I'm not quite sure about the difference of the english words as well.
Yes, that'd work. There's some overlap between them - most mistakes tend to be errors, for instance.