I think the Jags changed their offense in this last game. One of the link[s] you posted to a Jags preview early in the year talked about how Mularkey's offense used isolation routes exclusively. As you know isolation route are WR routes that do not work off of each other (ie. pick plays, moving the safety off his spot, etc). Isolation routes put more pressure on the WR to get open, because they don't get any help from the routes working together. I believe you made a comment about how that's not a good idea for this weak WR corp.
I've got great seats at the Jag home games. I can see the WR routes develop really well from my seat. And I'm telling you that the Jags were running isolation routes pretty exclusively in every home game this year. The WR were having all kinds of issues getting open and were getting no help from the offensive scheme.
But yesterday's game was different. The WR were definitely not running as many isolation routes. They were running pick plays. They were sending a man deep to clear up room for mid-range throws. And the WR (especially Blackmon) excelled in this gameplan because the pressure of getting open wasn't all on them. I also think this is why Houston's defense struggled to adapt. They hadn't seen any of this out of the Jags offense on film this year.