It's VERY common for breeders/owners to not realize(? maybe some do but keep/breed them for various reasons?) that some of their turkens are not pure for the naked neck gene. I see pictures of breeders/flocks that eggs/chicks being offered from that are not pure quite often. So even if all the "birds in that pen" have naked necks, these still can throw some fuzzy necks.
Another common misconception said about turkens is that only the pure ones have totally bare necks.. there are many pure ones that have small bowties.. the visual difference between a not pure and a pure is the size of the bowtie. Pure ones have a tiny bowtie and the not pure ones have a huge fuzzy patch that covers most of the front of neck and are overall "less naked" than pure chicks. I'll add pictures of day old chicks to show the difference:
Pure on right, not pure on left.. notice the one on right has clear area below bowtie and also a naked space between eye and beak.. the darker one has a huge bowtie, plus her face is solid fuzzy:
Pure one, this one has a very small bowtie, could appear totally bare necked but if you look, can see tiny puffs of bowties up on neck:
I only have pictures of chicks right now but the bow tie size difference can be seen on adults too.
So it could either be egg mix up or the breeder was not aware of this or didn't mention it.