Yeah it's given offside against the corner taker, after the Wolves number 11 heads the ball (backwards or forwards, it doesnt matter what direction the ball goes in) the corner taker is deemed to be offside. It's common that corner takers often fail to get back onside in time when the ball comes back to them.
However, look at this pic below. You can just see the corner takers head at the bottom of the screen. The wolves number 11 has just headed the ball (unfortunately Nunes doesn't come into shot the exact moment he heads it but its literally a split second after).
You can also see the linesman legs at the top of the picture.
Then look at where "Trent" is.
Now it's a possibility that if Nunes was sprinting full speed from being offside about 2 yards deeper when the ball was headed then he is now a split second later he could have been offside. But it's very doubtful i'd say.
Plus regardless of if he was or not, there's no way in hell the linesman can tell from his angle, he should be in line with TAA but is in a poor position so he's either guessed badly, or was just wrong.
But IF there is no better angle then they couldn't overule it on VAR with this. And IF there isn't a better angle thats disgraceful from the FA/PGMOL or whoever is in charge for not ensuring that there is 100% coverage of the pitch.
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