So sorry for the angst, disappointment and now inconvenience of having to deal with this, Ian.
This bend is in the unsupported rear section of the rack, a section intended primarily to support the taillight by mounting it rearward to a point where it is not obscured by the panniers. As a bonus it extends the length of the top deck and gives another lashing point.
Based on my experience bending tubes as a hobbyist framebuilder and rack maker using cro-moly steel, based on the photo I think you could pretty easily bend that back into place after uncoupling the last bolt-on crossmember. In the absence of cracks I don't see a major problem, provided the rest of the rack is straight. Check to make sure the steel is good, as the powdercoat may show signs of being strained past its plastic recovery and that can look like more major cracks. If the rest is bent, it may still be easily recoverable but other methods would need to be employed. Instructions included with Thorn's(front) racks remind the user the racks are heat treated and this can sometimes result in misalignment that can be addressed by bending. I recall seeing a photo with someone, possibly Andy Blance by memory, standing on part of a rack and heaving up on another portion, so I would not be shy. I'd probably demount the rack to work on it and use wood as a fulcrum along with my boot to avoid scarring.
At the same time, I'd place a claim in case you don't wish to pursue a DIY remedy or to make you whole if you cannot get it to work satisfactorily.
If 't'were me, I'd also check frame alignment as a general precaution in case I needed to extend my damages claim, though I would be very surprised if this is affected it at all. The Nomad's frame tubing is large-diameter and robust and the 19mm seatstays particularly so. Though shaking to find and see, if the damage is limited to what we see of the rack alone, it is actually pretty minor and easily addressed -- a good sign.
Hopefully helpful,
Dan.
