I got this metaphorical story from my friend Orion. Suppose there is a cadre of mob criminals. They want to communicate about their plans for a new heist, and do it securely. So they all pile into two cars and set off for a deserted highway. It's reckless, but they start communicating about their next job by flashing morse code with their headlights. Everybody signals "OK, we got it!" at the end and this is the only conference they ever have about what turns out to be a bungled heist where a bystander is killed.
If these mafia members can be caught and it can be shown that they had this morse-code conference, can the Transportation Agency responsible for the highways be held liable?
This story is on my themes, somehow. I'm not going to take too much time mulling over right now how, but I wanted to get it down before I forget.