The only thing i can comment is on the picture. The fact that he is claiming it was a different gallon is nonsense...yes that can potentially cause a sheen difference, but not to the degree that i see. He either used something other than satin, or he didnt mix the finish well enough before applying. A finished product shouldnt have any rough spots, should it be absolutely smooth like glass? not really. but you should be able to take a tack cloth across the floor and not have it grab. The rough spots, could be from poor prep of the floor before the final coat, or too thin of application of the finish. Unfortunately they need to come back out and just re-coat the entire hallway. I really dislike the fact that they used blue tape on a freshly coated floor. If you read the inside of the tape roll its SPECIFICALLY says not to use on hardwood floors that the finish is not cured.

Thank you for the comments so far! To be clear it was not a refinishing. The floor was put down and finished by the same contractor, meaning this is the "original" sanding. Would you live with it? Given it's been 2 years already I am thinking we don't do anything until we re-sand. When we do (re-sand) will it be hard for the new contractor to fix it? I'll ask about hardplate (and I also read about oscillating sander?). It's quite odd that we only see the marks in one area of around 10% of total surface area...perhaps due to the light in that area only. Moving forward I guess my main worry is that the next sanding in a few years makes this worse and not better. For the life of me I cannot see a difference in height and was hoping you'd all tell me it was either the way stain was applied, or the poly. Also, @Sye Phommachanh what are "dishouts"? thank you!

Your swirl issue is from buffing before the staining, not between urethane coats. There's a fine line between buffing too little and ending up with a good color and swirl scratches, and buffing too much which gets rid of swirls but ends up too light. Floor sanding is essentially scratching the wood with smaller and smaller scratches. When staining, you'll almost always have some scratches if you look close enough. That's why G&S mentioned inspecting from a standing position. Inspection is also done under normal lighting conditions. In general a 100 grit screen should be smooth enough for the last sanding (though I generally fold it and rub it together and avoid starting where it might show swirls), and I wouldn't recommend going finer than 120. Water popping after 120 will help achieve a darker color. Some guys swear by applying stain with a buffer and pad but I've seen more swirls result from that technique. I prefer applying with a trim pad or lambswool and wiping by hand. Right before the final screening, the floor should be vacuumed, and anyone entering should avoid tracking in any grit that could end up under the screen on the buffer. Also pay attention to whether opening and closing doors could pull in grit from outside or from under any trim.

Hard to tell from pictures, but it looks dirty. If I hadn't seen your claim that only water has been used I would suspect an incorrect product had been used. if you spray a spot with ammoniated window cleaner and clean it with a white paper towel, does any dirt end up on the towel? Does the cleaned spot look any different? This is a vexing issue, unlike anything I've ever seen, with that pattern on the floor. I'd discount the possibility of material issue or application error as I doubt it would cause that patterning. I recommend buying Woodwise cleaner concentrate and using it regularly to see if it makes a difference. I don't know how much traffic you have, whether you have pets and/or kids, and whether you have proper walkoff mats at entries. Or maybe it's one of two people in the house who take off their shoes every time they come inside. Regardless of what's causing your current issue, you'll need to use a cleaner on the floor, as plain water is insufficient.