Actually it's about circumventing the tool, not breaking it.
In this case the practice they are talking about is called, "Piggybacking", and "triangulation". And yes it does work.
No, I wouldn't say Tor could be broken without some time, and an understanding and direct copy of the software server. But, governments aren't stupid as how they can easily identify where those "volunteer" servers are located and corrupt them at a local level. After that, it's all "catch and release, info".
It's cloak and dagger of the 80's age. It was easily used then, it can be easily used now. Today's programs are more complicated, but they are usually weighty in nature, with far more coding now then 30 years ago. The more lines a program has, the higher chance of a sophisticated attack on a part of it's structure. In other words, the bigger isn't better. And the greater amount of line code does not denote it's quality of purpose. Just means there's more than one way of attacking it.
Why are you all acting like, "I'm a smart hacker, I KNOW how things work, i'm smarter than the average non-computer lingo muggle...."
Really? Every security measure ever created was always either broken or circumvented. Acting like Tor can't be broken or circumvented, is pipedreaming. A computer code is only as good as it's programmer. Since all programmers are HUMAN, then to error is human. Or in this case to Err, was strictly a human programmer who had limitations of either brain capacity, hard drive space, or was to full of EGO.
Human + Ego = Err
=^o.o^= When I'm cute I can be cute. And when I'm mean, I can be very very mean. I'm a cat. Expect me to be fickle.