I heard about that too.
People on the av club theorizing that walter was high and ...well, Walter, and since Olivia was there fighting the Observers/Invaders right there with him, that she knew the CORRECT coordinates in the first place, once there was a callback to them
They faked us out on the memory thing this ep though, with Olivia at first pretending to not remember the name fo the restaurant with the best Apple Pie (Donnovan's). I was CONVINCED with that, and the stuff with the remembering of the Invasion Day differently that it was a different Olivia/timeline. Then turns out she knew, she just didn't want to re-live it.