Is this a normal way to meter during the golden hour

[Gunfitr]

Taking a reading from the front would give you the light falling on the model.

Taking a reading from the dark side, would give you the light reading in the shadows including any ambient fill from any nearby bounce surfaces.

Knowing both would give you a contrast ratio. The shadow side opposite a light source isn't always zero.

Without seeing the exact set up, I don't know what he was doing, but I often taking reading from the "light" side, and another from the "dark side" for a variety of reasons.

Maybe your haste to judge him is based in part on the first sentence of your post.....something about you questioning him about whether he had permission to shoot there.

Maybe he thought you were questioning his right to be there.....which really wasn't your place, if you too were scouting locations.

Mark