Essentially, in that case both of you are locked in a state with almost no kinetic energy and some potential energy.
In this case, clearly the failure is on part of the higher plane to attempt a roping - as the E advantage he is in is only worth about 200~400 yards of altitude higher than the enemy below.
Things start to look bad for the higher plane, if the lower plane is something like a Spitfire which can start maneuvering again even with small speed gain, and the higher plane is something like a Fw190 that needs a considerable margin of speed to reclaim to start maneuvering again.
The options for the higher planes are:
1) If the higher plane is a better climbing plane, then he may try to keep that state and slowly but firmly outclimb the lower plane.
2) If the higher plane is a better accelerating plane, he may risk falling under a temporary gun solution and level out, to accelerate and further distance between him and the lower plane.
3) If the higher plane is a better diving plane, he should keep a careful watch on the direction of the nose of the enemy below - the slight altitude advantage might provide a "head start" for him and enable him to get away in a powerdive.
4) If the higher plane has better maneuverability at high speeds, he could nose down, and urge the lower plane to follow him, and then try a quick reversal or escape, during the downward flight utilizing his superior high-speed maneuverability.
5) If the lower plane accelerates, maneuvers, climbs, dives better than the higher plane, then the higher plane is screwed.