I went to spend Christmas with my in-laws about ten years ago and ruined their meal.
I'm not a bad cook, I know my way around a kitchen, my mom ran a fast food joint when I was a teen and she taught me how to work my ass off in a kitchen. From that start I've developed into a pretty good cook (or so my wife and friends tell me). I'm not the best but I do know how to cook. I know how to make prepare and serve a full Thanksgiving dinner with all the trimmings and desserts on my own if I had to.
At my in-laws place for Christmas I knew I should help so I just started doing dishes without asking. The place was hectic, the in-laws barely know how to cook and none of them seem to appreciate any spice other than salt or pepper. Everyone was happy I was helping and I kept the kitchen clean as the cooks worked. It was familiar for me and it amazed everyone else.
After a couple of hours of helping I thought I'd do more. They were making gravy and all it was was thin water from the drippings mixed with flour which made a white watery tasteless gravy. I thought I'd amaze them by making a roux with the own drippings, thickening the liquid, browning it to a golden color, adding salt, pepper, spice, a drop of maple syrup, soya sauce and a dash of Worcestershire. I kept tasting it and to me it was delicious. I had practiced for years and I knew how to make it taste good.
The in laws came in and the room went quiet, even the Christmas music stopped .... they all looked at me like I murdered the cat and I was cooking it.
They were all upset that I had changed "Ma's gravy" and turned it into something else. Everyone was either disappointed at best or just sneered at me like I had thrown a brick into the living room window.
I didn't burn anything, didn't over salt, didn't make anyone sick, no fire, no explosions, blood or burns ... I had just ruined "Ma's gravy" of basically water and flour that everyone ate and somehow enjoyed every Christmas.
It was the weirdest TIFU in the kitchen I ever experienced.