1Dx or Lightroom moire-ish problem or just bloody unlucky timing?

Sty wrote:

Raw imported straight to LR4.2 (tethered actually, studio session), newest FW on the 1Dx. I've never seen this happen before on 5d2 on 1Dx. A lot of nasty purple stuff.
This did happen on the other veil shots but only on the edges, this is the only one where it's very very prominent.

There's a softbox on the left and umbrella to the right, Zeiss 50/2.0 at f8.