The shadow disappearing is probably not due to Clip to Camera, unless that one tree next to the church is actually a member of a population for some reason. Clip to Camera only affects populations, and only the members of that *specific* population with it enabled.
More likely it is due to the camera view clipping of geometry for shadows which can be overridden in the Render Node Advanced settings tab under "Ray detail region padding". In your case since the object ends up directly behind the camera you would need at least 360 degree detail, try "optimal" first, and if that's not enough use Highest.
- Oshyan