Question: Was it Rowley or really one of the kids who told the story of how the kids fell in the ditch?
Question: When Gregory was singing beautifully for his audition, did he really sing that well, or did he lip-sync from someone else singing?
Answer: That was not him singing, that was another kid singing.
Answer: According to wiki.celebrity.fm and diaryofawimpykid.fandom.com, L.J. Benet provided the singing voice for Greg in the movie.
Answer: Where did you hear that? Because on IMDb, it says that everyone EXCEPT Greg did their own singing.
Answer: That was Zachary Gordon's actual singing voice.
Chosen answer: As said in the film, it was one of the kindergartners who explained the whole story to their parents. It would seem that Rowley would indeed be too soft and cowardly to do such an irrational thing.