Count the fish - where would you put your fly?

This was taken from slightly above the casting position - about the only spot on the pool that allowed a cast. I was standing hard against a tree, the angler was standing at river level, between the roots of the tree.

His back cast had to reach between a bush and tree - a decent straight line cast put it below the dry rock in the centre of the stream. Suggestions?

Btw - he did hook and land one of these.