The original is correct. Your guess is the opposite. It says "nobody thought". Erika's restating of the sentence should give you an idea. Maybe the phrase 'for a moment' is confusing. It is just a way of saying nobody thought that at all.

Yes, the original sentence is grammatically correct. However, the phrase “about whom such a stir had been made” sounds a bit formal and uncommon in everyday speech. A more natural way to say it could be: “Nobody thought for a moment that Tom was the escaped convict who had caused such a stir.”

Corrected Version: “How do you do, native English speakers?” “Is the original sentence grammatically correct?” “I guess the original means: People thought for a moment that Tom was not the escaped convict. People had caused total chaos regarding the escaped convict.” Tip: 1. “How do you do ,native English speakers.” → “How do you do, native English speakers?” → Add a comma after “do” and use a question mark since you’re addressing people. 2. “Nobody thought for a moment that Tom was the escaped convict…” is grammatically correct. 3. Your guess is slightly off: The sentence actually means that nobody even briefly suspected that Tom was the escaped convict, despite the big fuss made about the situation.

Your question has already been answered. I just want to comment on the phrase "about whom such a stir had been made". It is not wrong, but it sounds awkward to me. It seems pointless to use passive voice since it is so clear what caused the stir. Passive voice only serves a purpose when you want to avoid naming an implied subject. Either state what caused the stir or make "stir" an active verb: "Tom was the convict whose escape had caused such a stir" "Tom was the one whose escape from prison had created such a stir" "It was Tom's escape that stirred up all the commotion."

No one has even for a moment considered that Tom could have been the escaped convict. The one that all the news and talk was about.