Fox vs Bird of Prey

East Herts. Driving along a B road in the sticks, saw a fox and large bird of prey wrestling in the top fringes of a large tree about 15 metres up, the fox then fell through the branches somehow landing on its feet, stood there for a moment looking shocked, then hobbled off into the hedges. Fox was large adult. Bird was Buzzard or Red Kite, we have a lot of Red Kites in the area. Obviously a very unusual situation. Question, which of the following could have happened?: Fox tried to take the bird from the ground, bird took off with Fox still attached? Bird tried to take the Fox (know this is not normal)? Fox climbed the tree to try to get resting bird (also know this is not normal)? What do you think??