Aircrew don't ALWAYS have the full picture.
Absolutely. I did a recent cockpit famil and came back to home base at the start of our evening rush. Looking at the TCAS and listening to the RT as well as looking out the window, I would have sworn it was us and two other aircraft. I even commented to the crew along these lines. The delaying techniques and levels used pointed to a very different situation as what we were told to do only happens when things are going bad. Spoke to the guy who was the controller when I next saw him at work and he filled me in as to how they were getting hammered. If a pilot thinks they have a proper traffic picture, they are sorely mistaken.