How do semi-technical decisions get made?

In a May 10, 2005 NYTimes column Kent Sepkowitz, M.D. tackled the difficult issue of whether doctors should withhold information from patients, and who is in charge when it comes to planning treatment. (The column, here, is already in the Times' paid archives.)
This issue is part of a larger topic, one that is quite familiar to many of us. In the business world and elsewhere, a decision is often made based on technical information provided by someone deeply familiar with the techy issues, and a non-technical person with knowledge of the issue, but little understanding of the techy stuff. It is usually close to impossible for these two to communicate, and yet they must, to achieve a good decision. (Of course the decision-making process gets worse when groups of people represent each camp.)

In the business world, the techy is, perhaps, the programmer, engineer or artist, and the other decider is a manager; the manager usually makes the final decision. In the medical world (until recently) the techy was the doctor and the patient had the direct, first-hand knowledge; but the techy used to be the one in charge. (Sepkowitz raises some doubts about how often the patient should be in charge.)
If you will relate this problem to any area in which you have technical expertise, it becomes clear at once that of course you do not tell the other decider "everything." It's counterproductive for either person to drown the other in all the relevant detail one can think of. How do you choose what's relevant without biasing the decision? Or should you bias the decision?
This decision process fascinates me. In every large company, as you go up the hierarchy, you will find barriers where the person above cannot possibly understand most of what the people below have to say. How does communication cross these barriers? And every time I need to make a difficult medical decision, I know I’m facing the same problem. I think that:

• The techy's challenge is to present the important information without overly biasing it.
  
• The other's challenge is to figure out how to react to the techy.
  

Now perhaps you think I SHOULD have said this:

• The techy's challenge is to present the important information in a clear non-technical way.
  
• The other person's challenge is to know enough about the field to understand.
  

But I didn't say that, because my experience is: it would be wrong. Illustrative anecdotes will follow!