Right-of-Way for traffic being overtaken
Hi, recently one of pilots reported my collegue stating that his FL was changed in spite of the fact that he was the one being overtaken by the succeeding traffic and according to Annex 2 to he has the right-of-way and he must keep his flight level. I checked Annex 2 but under the related section it is stated that the aircraft that has the right-of-way shall maintain its speed and heading. There is no mention of FL. In this respect I am a bit confused. Also in todays traffic flow it is not easy and logical for a controller not to play with the level of preceeding everytime traffic cause there are numerous variants like the settled spacing mimina with the downstream unit by the LoA. In our case the preceeding traffic was an A320 and behind that aircraft at same level there were two A38O's whose performances were much higher than him and going to enter another FIR through the same exit point with an agreed spacing minima of 20 NMs.
Does the right of way cover maintaining of FL and is it mandatory to apply it in any case even if it would be cumbersome and increase the worklod to apply it? Can anyone enlighten me on this issue?