You're absolutely right. It is not enough to use anonymity tools, you also have to make sure everything else around you doesn't compromise your anonymity. Made me think of a Harvard bomb threat incident where the student posting a fake bomb threat (through Tor) to avoid final exams was the only person using Tor on campus at the time, which trivially identified him.
https://theprivacyblog.com/blog/anonymity/why-tor-failed-to-...