Law 11 is clear on this
“a player in an offside position is moving towards the ball with the intention of playing the ball and is fouled before playing or attempting to play the ball, or challenging an opponent for the ball, the foul is penalised as it has occurred before the offside offence”
So if the ball was in play it would be either a free kick or a penalty depending on the location.
But Newcastle's gripe was that he was allegedly pushed in to the offside position and otherwise would have been onside. That makes all the rest irrelevant because obviously his position is only taken in to account as the ball is kicked, so if the push happened with the ball in play, there is no offside offence to penalise anyway (assuming it was only because of the push that he was offside)It would in theory, but what if the push was deemed to be not strong enough to be a foul? In that case it would presumably still be offside, even though he was manoeuvred into that position whilst the ball was in play.


