If there are some seizures of directory authorities or other project infrastructure, this won't be some totally unpredictable occurrence. It was only about a month and a half ago that some relays were seized as part of a general takedown against Tor hidden services. The Tor project posted this blog in response:
https://blog.torproject.org/blog/thoughts-and-concerns-about...
That blog post convinced me to shut down my relay. The reason is, to an ambitious prosecutor this blog post looks like:
"We view law enforcement operations as attacks and are looking for ways to defeat them, because we are determined to shield the identities of our criminal clients"
... which is exactly what resulted in the operators of the Silk Roads getting arrested even though they were not personally selling drugs.
The blog post makes casual reference to the "enormous social value" of hidden services and claim they're worried about "secret police repressing dissidents", but doesn't cite any actual examples. Actually I've never heard of a hidden service that has enormous social value - whilst there are a small number of .onion addresses that aren't completely illegal or unethical, for all the examples I know of the operators are not anonymous.
To police forces around the world who keep having investigations hit a dead end because of Tor, going after the project directly will not seem very different than going after services like Liberty Reserve. The people running it are stating publicly that they will do their best to frustrate investigations, and that is dangerously close to admitting participation in a criminal conspiracy. Thin ice doesn't even begin to describe their current situation.