Sorry for the delay posting. I arrived home last night at midnight, rose for work at 4:30 am, and just got home again not long ago. My subs even rode to work with me, I had no time to unload the vehicle until now. Many of us lost a lot of sleep over the weekend.
What we heard at the GTG was not the CS-18.T subwoofers, it was the iNUKE amp running out of steam. It was hidden from view with the subs and the clipping lights were not visible. I heard it during the test, but as the audition was underway, it was too late to stop.
I was positive something was awry and asked Archaea to help me investigate. He was kind enough to spend several hours with me the next day, setting up, putting the EQ curves in place, doing measurements, then running the program material over and again, trying to recreate what happened. We tried the Dayton, then we tried the iNUKE. The Dayton was a little light on the bottom end (Bass Boost off, Audyssey left the natural room response basically untouched), but no untoward sounds were made, during music or movies. The iNUKE sounded better than the Dayton on music, as it gave a needed 4 dB boost centered at 20 Hz. But during some movie clips, what sounded like bottoming occurred.

It can be difficult to distinguish the sound of an amp hard clipping from a driver bottoming, they both sound very similar. With the amp in full view, it started to become apparent that what we heard during the testing was the iNUKE clipping HARD. Still not sure if it was the driver bottoming or the amp running out of steam, we grabbed a flashlight and sat right in front of the drivers, running the "Bass I Love You" clip over and over. No bottoming, everything sounded good. Running the "Skadoosh" scene, the amp clipped and the subs made a horrible sound. We did this over and over, checking both subs. I am positive that what we heard was the amp clipping and not the subs bottoming. More excursion was had from "Bass, I Love You" with no bad sounds, less excursion was had from "Skadoosh" with bad sounds. This was repeated with the "Iron Man" missile launch clip, the iNUKE pegged it's meters and the CS-18.T drivers reproduced the sound of the amp clipping... quite faithfully. It didn't sound good. Luke Kamp showed up and we replayed the movie clips. He felt the same as I, Xmech wasn't reached and wasn't the cause of the untoward sounds we heard.
I owe Craig and everyone else an apology. I wanted to experiment with the iNUKE and it's DSP. This was a bad time to do so, it was my mistake and I own it. Had I run the Dayton instead, I feel we would have scored higher.
A positive outcome for this was, I do feel that the DSP the iNUKE has is beneficial. With more power behind it, this would have been successful. I feel strongly enough about this that I will be experimenting further. On my own time, not during a critical listening audition.

The takeaway from this is, the Chase subwoofers did not get a chance to put their best foot forward, they were hobbled by a poor decision. The scoring during the test and the test itself was completely fair, but the low scoring does not accurately reflect the performance of the 18.1's.
I edited my reserved post on the first page.