Look at the highlights on ifollow, definitely off side.
Do the ifollow highlights have better angles than the other highlights?
The one on Youtube I saw doesn't show the pass and scoring player in the same shot. From when he kicked it and applying scientific assumptions and total guess work, he was probably level or even in his own half when the ball left the guys foot. Either way, certainly tight and you shouldn't be relying on springing an offside trap exactly on the half way line.