"...But it did not create a retail panic see off..."
IMO, It's just an old-fashioned "shake"...nothing more, nothing less. Of course 40,000,000,000 shares will add a little more "shock and awe" to it, but at the end of the day, NITE was simply stocking up on a fresh load. I personally feel a lot of people had been getting very nervous for some time. I don't think they expected the bid to fall apart as quickly as it did...this triggered a lot of sells from people who wanted to salvage at least something before it went "no-bid". A "no-bid" threat IMO will trigger a shake like no other.
Also, just because NITE wasn't actively trading on the bid/ask for the past 10 months, doesn't mean he hasn't been in the picture...in fact, his absence, moreso confirms that there has been a game going on the whole time. How convenient that all the other MMs essentially parted the waters so little 'ol NITE could be there to gobble up ~ 1/2 the float in one day.