What about "tort law" don't you understand, Major? ;)
As Rickair said, we don't know what a court will decide until a victim files suit against Big Wig for running over him while driving his rental Hummer drunk as a fish after drinking the entire flight to LAS. My concern is for the regular Joe Blow PIC and what he should do if ever faced with something like this. If he does nothing, he may be held as liable as if he did do something. Damn if you do and damn if you don't. And by the time he finds out, they are 35,000 feet in the air.
We drew a line between illegal activity and immoral activity, however there is no bright line rule for how a PIC ought to behave. At the end, I suppose it comes down to the individual person and where he has set the bar for himself. I hope private airplane companies have some guidance in their personnel manuals.
I'm going for a margarita now.