..seems it was expunged from Google...but FR has it.
I'd almost bet they have a dump protocol action command somewhere along the line which sends some stuff just part-way (thru 479,272 "hits") down the memory hole. Plausible deniability, and all that...with as time goes on, the number (hit number where an item could be found) downward increasing towards infinity hell.
I'd bet only a few on the Google campus know of the secrets of that inner-circle, special order admin op.
There could even be some lone wolf types, along with some ad-hoc cabals who have the capability of doing the memory hole dirty work, so do so, without anyone in management directing the proceedings in any way, which gives them another layer of plausible deniability.
What we could really us is a handful of whistleblowers inside Google, who would be crafty enough to "stay on station" sort of like double-agents, after the credible info was leaked. There just has to be some geek turned code-toad who would relish that sort of thing.