People should have noticed the missing Gibbs for the first 2 goals and the penalty. He was caught up the pitch where he shouldn't have been.
Cazorla gave the ball away cheaply for the second goal, and they blamed Kos for backing off but that is because Gibbs should have been there making the tackle/pressing the player with Kos as the back up. Kos couldn't commit himself because there was no cover. Gibbs was truly shocking in the till he got the sympathetic red card from the ref. He has all season and for 3 years done the same, his positioning is terrible, for someone to push so far forward against such a good side in a situation in which there is not even a good chance the ball will make it forward is disgraceful. He's pushed forward to support before the ball has even gotten forward and been caught out. Kos/Mert weren't great today but they were given exactly no cover at all by both fullbacks, the entire midfield.