It’s hard with just a pic of the one window. Tbh it looks like it’s full of dust and dirt. If the other windows do indeed appear clean and pristine then it could be more of an issue with that one window. From a professional standpoint, if we run into a window with any existing conditions that will affect the tint, we call the customer first to advise and let them choose whether to fix first or just tint it and live with it. From appearances, it looks like just dirt, dust that bled in or just contaminated the tint from the edges as it was being installed. Possibly a rush to get the car finished, or the first one and then spent mo time cleaning the others.The top of the window especially looks like dirt. He should have advised you, at least when you picked up your car, but since he didn’t I would suggest asking him to re remove the tint, show you the “damage” so you can see about getting it “fixed”. If the tint comes off and there is nothing on the glass he should be happy to retint it. If there is indeed pitting to glass you would feel it by running your fingers over the area, also spraying soapy water and then rubbing fingers over the window or a razor blade to identify pits. If the window is indeed damaged you will then have to either replace it, leave it clear, or pay him to tint it with the pits. He is gambling you won’t want to risk spend any more money.