Which is worse, the very poor story, about this vague theoretical threat, or the dubious comments?

Yes, you can sabotage lots of things, even secure computer based dispatch systems, if you have access and time. Most of these systems are not easy to access, and the more time you spend trying to access these systems from an outside network or account, the more they are likely to trace and track your attempts. So, I'm not going to lose much sleep on this one.

There are very real and big threats to our transportation systems, as so many recent events have shown us, and this possible "threat" is probably not at the top of the list of things most transportation security folks are worrying about this morning.