Mike Schumann wrote:

Also remember the mid-air in Switzerland a couple of years ago where the
controller took a break in the middle of the night.

Are you stating that the only controller on that night took a break, which
led to the mid-air?

If so, that is incorrect. There was one controller and he was working both
the high airspace and an approach. The controller couldn't reach the tower
of the airport to properly hand off an Airbus flying the approach, which
raised his workload. When he spotted the potential conflict between the
Russian aircraft and DHL 757, he issued a descend command to the Russian
airliner.

Roughly at the same time, the copilot of the DHL 757 left to use the
bathroom, and when the TCAS alert sounded in their cockpit, the flying
pilot responded but did not make the call that they were descending. When
the copilot returned, he made the call, but was stepped on by another
transmission.

Don Brown has a column about this accident and he describes all the links
that led up to this accident:

http://avweb.com/news/columns/191072-1.html

--
Peter