번역:He did not even say one word.
"He never said a word." should be accepted as well?
Yes. That makes sense. However, the translation of "그는 한 마디도 하지 않았습니다" to English is slightly off from yours but they both give the same idea so I believe it should be fine.
he did not say a single word. why is this wrong tho? XD
Even 빠뜨렸는데 통과되네요 20180202
He did not say anything