Well, he's right.

The gap is there so water does not absorb into the wood.
All homes should be done this way with a 3/4 inch to 1 inch gap.
My company only uses copper flashing so it shows itself, not that shiny tin everyone sees from down the block.

Now you get to paint them, and the window.
Good contractor

, usually they do it wrong so they can replace the wood siding in 5 years, keeps em busy.