That should be the root radical, and be planted down. I.E. it comes out of the "pointy" end of the nut and then turns down.
Mostly like that should correspond to the "flat side" of the nut being down.
Hope that makes sense.
look at 2ndhand's photo in his thread:
You can kind of see the round side is facing up, the growth of the root and the top side plant both come out of the "pointy" end.
If for some reason the root is out and it turned towards the round side I would put the round side down versus having the root try to reverse direction.
Most of the nuts I got from bigeight, the root was either just starting to come straight out or turned towards the flat side.