That only proves that failed bidders bid below the market rate. If anything, these bitcoins carry a premium for the same reason that "tainted bitcoins" carry a discount.
The fact that Tim Draper won every single lot in that Silk Road auction suggests he paid a premium.
Who knows? I do remember keeping a close eye out and everyone who spoke of their bid said theirs was under market. Can't remember how many said anything but it was a few.
It doesn't really mean anything. There'll be good days and bad days when the buyers don't show up in the same numbers. It's not much of a reflection of the market elsewhere. There's only so many buyers at this level and only so many who bothered to qualify.