Indentations from a floor nailer?

Q: We had a new hardwood floor installed three weeks ago. When we got to installing the baseboards we noticed hundreds of indentations. Could they be caused from a floor nailer? We haven’t used the room so it isn’t us that did it. How could these indentations occur?

We checked an open box of wood left over and there were no scratches on these.

They are everywhere, some the whole length of the board.

A: Could be from a floor nailer, unless they are round dents appearing even in the center of the boards, in which case it may be high heel dents.