The diffuse is shadow disabled (Of course).

The infinite "sun" (Or moon in this case) has shadows enabled set to 100%.

The two lantern point lights have shadows enabled, too.

I've seen things go wonky when I tried IDL with non-GC-multiple infinite lights lightsets where the shadow strenght of the sun was set to 120% or more

But these "new" GC lightsets all use only two lights to illuminate the scene.