I'm pretty sure I saw these in person when they first came in, back in March. Here's a photo of them at the LFS:
Strangely enough, IIRC they had 5 of them.
I am 99% positive that they aren't gigantea. I also don't think they are haddoni, given the amount that were imported as folks have already mentioned, but also because they didn't "look" like haddoni. Granted, we haven't seen baby haddoni (not this small) and I've never seen a red gig, at any size, so we can't say with 100% certainty what these are.
Speaking of baby haddoni, another LFS had a "baby carpet" back in December of last year, and it looked a lot like a haddoni to me:
I considered buying it but I thought it would get lost in my 120 gallon tank since it was only about 2" (not to mention that they wanted $300+ for it).
It's hard to explain, but now that I've seen quite a few gigs and haddoni, I'm having an easier time telling them apart, and I now have an immediate "gut reaction" when I see Stichodactyla. These nems didn't give me that "gut reaction".
So, if I were to guess what these are, I'd say mini-maxi.