How do you know it was nail if its been tapped and finished?
Often some of the edges are nailed as its easier to hold and put a couple of nails in. once its "holding" in place then the screw gun comes out.
That would still be considered "screwed".
My dad was a drywall contractor, I worked in the biz for quite a few years.

Good question.... We have close up pictures prior to the finishing layers. I just assumed all drywall was nailed until I was rereading my contract with the builder. It also had the characteristic dents/crushed wall that a hammer makes at many/most of the nailing spots.

In an effort not to assume, I will ask the builder and superintendent to ask the sub what they used.

The pic only shows nails at the perimeter, which is where nails are often used even when the rest of the installation is done with screws. Building/renoing for 30 years I would never have thought to specify screws only as that's all I've ever seen used. Live and learn!

Ours was screwed and they still pop. Annoying.