if you find yourself in a position where the boss expects you to fly on company business,
Absolutely right. The explicit provision is that the trip should be possible and make sense even if you did it by car or public transport. Nobody, including the pilot, can be forced to make the trip by private airplane. Otherwise you're indeed in deep water.
The other thing that you need to consider when doing this kind of thing is "dispatch reliability". Private car trips, airline trips and public transport trips all have a dispatch reliability of well over 95% - meaning that if you plan a trip, there's a chance of well over 95% that the trip will go exactly as planned. And if for some reason the trip doesn't go as planned, it's usually because of a condition that everybody understands.
Private aircraft, especially when limited to VFR conditions, do not have these dispatch reliability numbers. You have to make sure that your boss and your destination understand this, and that a thing like "it's a bit murky" can, will and should be a valid and unquestioned reason to cancel the trip. And of course, trip times being what they are, by the time you've decided that the trip cannot be completed by private aircraft, it's usually too late to switch to a car or public transport journey.