When I worked in Santa Barbara County, I would frequently be called out to consult on City of Santa Barbara projects. these were public work projects such as the construction of roads, replacement of sidewalks, construction of sewer lines, etc. One of the planners, a fellow whose name I can not recall (which is just as well, as my sense of ethics would prevent me from including it here without his permission), would always ask the same question:
"What is the worst case scenario, from a historic resources standpoint?"
Each time the conversation would play out the same way. He'd ask the question, and I would talk about what was likely to be found. For example, I was once asked to explain the "worst case scenario" for a new sidewalk installation. I explained that the proposed sidewalk was on a road that traversed a steep hillside with no rock outcrops or caves, meaning that the odds of there being an archaeological site was very, very low. Therefore, I couldn't conceive of a "worst case scenario."
"Well, what if we find an Indian cemetery while working?"
I then explained that this was rather unlikely, as people who don't have heavy equipment tend not to bury their dead on 60 degree slopes with no caves or rock outcrops.
"What if this was the exception? What if there was someone really important and special, and they made the effort? What if this was a group that thought it was religiously very important that everyone be buried in a steep hillside?"
And so it went.
This was typical, I would be asked to give a worst case scenario, and when I explained why the situation wasn't dire, I would be faced with a question about an absurd situation which I could pretty much guarantee would never happen, and I was asked to provide a full plan for how to deal with it, complete with budget and schedule (seriously, I was sometimes asked for a budget and schedule for dealing with things that didn't even exist).
The problem is that if you are going to play the "we have to think everything through, no matter how unlikely" game you will never reach an end point.
What if you find the site that provides actual, legitimate proof that the Knights Templar fled France and settled in California? What if you encounter the remains of a neanderthal who managed to migrate to the Americas? What if you find a site that contains clearly unearthly material, proving aliens landed? It's absurd, it's silly, it's stupid to waste time considering it, but if you are going to consider every possibility, no matter how far-fetched, you can't rule it out.
The problem is that, in archaeology, even things that are likely can't be worked out until they are certain. If we do find a burial ground, I can't say how it will be dealt with until the most likely descendants are contacted and consulted, the number of burials is known, and the potential for modifying the project to avoid impacts is assessed. In other words, asking for a "worst case scenario" before anything has been identified in an area is a bit like going to the doctor and asking for a worst-case scenario before he has been able to examine you or heard you describe the symptoms. And you know, I can kind-of forgive construction contractors or land developers when they ask these questions. they may not have dealt with this before, and they may simply be trying to wrap their minds around it. But a city planner who has dealt with countless archaeological consultations? Different story.
This is a situation that I don't find myself in very often, but it does happen, and it's always annoying.