Oh I see! sorry. I was looking at the wrong shadow. I was looking at the pointy one going across the stone. Because that points to it in the first photo.
I didn't notice the line going across the notch itself in the second photo.
So that's more convincing.
It was your mention of the 'needle' that confused me.
But what time of year was this? I know that noon is always the highest point the sun gets too. But it doesn't always get to the same angle from the ground does it, that depends on the time of year does it not?