I'm not sure we're watching the same videos then. I've tried looping the Amira footage, but the only thing I can see moving is the rise and fall of her chest and a bit of noise dancing about, I can't spot any moire patterns on the Amira footage.
Are you watching it at 1:1 pixel ratio ?
I can post a few AMIRA 4K 1:1 pixel crops if you want to see the AMIRA moire move.
Also, why would the seams only be visible in one small section of the AMIRA footage ?
...And why would the Varicam footage show NO seams in the same area of the image but show moire in a lower section of her shirt ?
When I loop both sections I am seeing monochromatic moire for both cameras.