Tom, while I appreciate the time you have taken to set out this thought experiment, it does not follow that being able to see the top of the saucer at a distance means that laser light rays from a plane can bend around and strike the bottom of the street light from up above. You have taking basic perspective properties and stretching them beyond reality.
I've provided illustrations for my explanation:
Firstly, it cannot be denied that when an overhead body flies into the distance, you will eventually be viewing its side.

In the above image the flying saucer recedes into the distance until, at a far off point, it appears that we are looking at it from the side. Perspective has reoriented the craft so that rays are reaching from the TOP bubble compartment of the saucer to our eyes, despite being at a lower altitude than the craft. If the cockpit had a clear glass window we could see inside.
Replacing the eye with a street light...

Perspecitve, having reoriented the flying saucer to the side also allows the saucer to view the street lamp from the side. The flying saucer can see the UNDERSIDE of the streetlight, despite being at a higher altitude above it.
Hence, both objects seeing each other from the side, the UNDERSIDE of the streetlight can see the TOP bubble compartment of the flying saucer and vice-versa --- light rays are passing between those two areas.
If we were sitting in the bubble cockpit of the flying saucer we could take a laser and hit the underside of the streetlight. Light is passing between those two areas, otherwise we would not see it.