The whole point of the judge’s statement wasn’t that writing in a different dialect was impossible but rather that it was very unlikely to be done in the given situation.
Remember, the prompt was supposed to be hidden to the contestants. So added with the fact that a live audience was watching them compose a story with a prompt that they were given on the spot, people under this kind of pressure tend to fall back on what they know.
Back in high school, my Language Arts teacher gave us 15 mins to create a short story based on the prompt we picked from a hat. I got the prompt “Hair” and immediately wrote about how a cute curly, dark haired child - in a family made up of straight, light haired people - woefully felt out of place while standing next to her brother at a mutual friend’s birthday party. The reason why I’m bringing this up is because I, myself, had a similar issue with feeling different than the people in my family.
Unlike Tang Mengji, I fell back on my own personal experience due to being crunched in time with an awkward, one-word prompt. The only reason why Tang Mengji didn’t do the same as I did was because: 1) She was given the prompt beforehand and was able to prepare in advance, 2) She had completely plagiarized a story that was similar to the prompt, or 3) Both 1 and 2.
(P.S. I take the different dialects thing like Kanji vs Hiragana in Japanese. The same language with the same tone but different written characters. Idk now to explain it better, but it makes sense in my head)