If I'm not mistaken, it's only offside when the player(s) are obstructing/interfering with play at the time the ball leaves the foot of the striker. But I had a look at the Fk a couple times. As Mata strikes it, the three offside players who were obstructing with the view up until then, did move forward and away a little towards the right. So Technically (it's all about technicality I guess), it can't be judged offside since the keeper had as good a view of the what's infront of him at that moment. Their presence there obviously tricked the keeper into thinking that the ball would come to his near side. That's on the keeper though.
And I don't see what the fuss is about by using Midgetland's ideas. The most innovative FK, corner routines, celebrations have all come from the lower leagues. They don't have the quality to execute it to perfection, we do. Can't believe a thread has even been created on this. I actually opened it thinking the OP was praising the routine. But God, anything to beat the old man with eh!