Bekolblockage. Not sure what you are getting at?
In a very basic nutshell.
The Cleared Flight Level (CFL) is the level the aircraft is cleared to climb or descend to. For the controller not having jurisdiction, they will base their separation with their other aircraft on this (in most cases).
It is usual practice that when an aircraft is within a certain distance to your airspace the controller who will give you the aircraft cannot change the CFL without first checking with you. I see an aircraft approaching cleared to climb to FL130, the other controller cannot assign a higher level without checking with me first. I can assign FL140 on descent.
Is AFL Actual Flight Level? If so , on a quick think about it , I can't see any situation where I would separate on AFL? I would base separation on what the pilot is cleared to do, not what he is doing right now. How could I ever have separation assurance on aircraft nose to nose, if I didn't know what the climbing aircraft was going to stop off at.
Not being privy to this incident, it seems as if the receiving controller was separating based on a CFL that had been incorrectly entered. One aircraft was climbing/descending to a higher/lower level than thought. When that aircraft busted the CFL (not the pilots fault BTW) the incident happened.