For reference, the "Helicopter" angle at the ~50s mark is amazing. http://www.espn.com/video/clip?id=21735279
Based on the helicopter angle, I do think he's leaning into an offside position, but I think it's several inches less than the half a yard that was modeled elsewhere. Either way, there's still no angle that makes me say with absolute certainty that it was wrong to keep the flag down.
Let’s be clear. Under no scenario would putting up the flag have been correct. Wienckowski deserves all the credit in the world for following his training, recognizing an impossibly close call, and correctly leaving the flag down. In any previous MLS Cup, we are lauding him for the hero call. Even Gantar did everything correct. There was nothing clear and obvious about this. Call stands. So he gets credit. The only question is if this call is different at the WC or other FIFA events. I suspect it would be.