Looking through the staff directory, I don't see a fact checker, but they do have copy editors.

https://arstechnica.com/staff-directory/

The job of a fact checker is to verify the details, such as names, dates, and quotes, are correct. That might mean calling up the interview subjects to verify their statements.

It comes across as Ars Technica does no fact checking. The fault lies with the managing editor. If they just assume the writer verified the facts, that is not responsible journalism, it's just vibes.