It's quite clear when the "workaround" was launched.
Thus, speculating on possible reasons for the outage should not be linked to Vringo with respect to a "workaround".
And if you check out pgs. 5-6 they explain how the "workaround" functions, further sworn to and publicly described in Furrow's declaration, which is 940:
However, Lang's patents are not just a matter of code / removing certain ads from a pool of possible options -- they describe the process by which an ad is selected; they provide the architecture for the entire system's methodology.