QC is, and always will be, hit and miss with every company. I don't know about you guys, but I can find a blotched paint app or loose joint (or some sort of slight production issue) on every single figure or piece I have ever owned.
Rather than complaining that you might received a helmet with a slight gap (that apparently can be fixed), you should be happy that NECA has even put forth the effort to have it fixed for the figures that haven't already been assembled.
In my opinion, most companies would not concern themselves with such a small detail...especially not on a figure like this one, which has so much detail and such laborious paint app requirements.
Can you imagine the extra time/cost and risk of damage to already completed figures if tired workers had to disassemble and reassemble figures they already completed, over such a small detail, it's just not something the company is going to do.
That said, I hope my visor is not gappy, but if it is, I will do my best to fix it myself –_it's not something I would demand a refund over, or send back to the retailer, and it's definitely not something that would make me second guess purchasing the figure.
If it was 200 dollars, then yes, I'd probably be more concerned over it, but considering what we're getting for $80, complaints really are not justified on this "gap issue". It looks damn good.
IMO.