Pete, I see things from your point of view, and definitely bow to your experience in matters like this. The details that emerged in your last post at least cause me to re-think my response and put myself more in the measurer's shoes. I certainly wouldn't want to be at risk for much more than my time and some mileage.
The obvious lesson to any of us that might be tapped for something like this is to make sure you have time and have arranged for contingencies- or turn down the assignment. I'll at least know what questions to ask should I ever get that call.