One of the things you'll hear often in the publishing world is that it's an "incestuous" business. What exactly does this mean? It means that yesterday's editor at House X could be today's editor at House Y, an agent at Z Agency, or even the latest new sale author competing for the same publishing slot as you. Everyone has a tendency to bounce. So when you meet all these professionals, you know to behave and watch what you say.
But what if Editor A requests a full of your story, but then switches houses? It happens all the time. And what if her replacement, Editor B, rejects your story because she doesn't like the very angle Editor A loved?
You suck it up and move on, grasshopper. Don't complain, don't badmouth Editor B for the rejection. Don't whine about Editor A's move or her poor timing. Because you never know when the two will get together and talk. And you don't want your name to come up unless it's to discuss a bidding war!
So keep yer big trap shut, keep writing, and keep your reputation solid!