West Brom boss Slaven Bilic admits they paid for the "many mistakes" in their 5-2 thrashing at Everton.
The manager offered no excuses after the humbling.
Bilic told BBC Sport: “We did so many mistakes we can't do at this level.
“Why I'm frustrated is the way we were tactically in the first half, we were closing them down, passing the ball, the way we pressed them, it can't be 2-1 for them. To show that naivety to go down after we are 1-0 up and to get the red card is frustrating."
On the Kieran Gibbs' red card, he continued: “He can't do that, he's old enough. He's experienced. He played a great game until then. He reacted to something James did to him but he wasn't clever enough to go down when he clipped him. He reacted and gave the referee no choice. It was our mistake."
On his own dismissal, Bilic said: “The analysis guys told me it was a foul for us before their first goal. They should have seen that Dominic Calvert-Lewin is going for the ball and doesn't touch it. The reason Darnell Furlong is heading towards goal, it's a foul.
"As a manager I should be in a situation to ask the referee what's going on. It's not like the game was going on, it was half-time - nobody was around. I didn't swear. I asked him in a frustrated way but I didn't go over the line. But he just ignored me and gave me red. As a manager you have that right if you are not crossing the line. I told him if you want to kill us, kill us. That's all.
“We showed some naivety. We had enough players to defend the set-plays. We saw everything in this game – a lot of quality, a lot of things to be proud of and build on. Just copy and paste in next game. But unfortunately there are enough things we can't do on this level.
“We have only ourselves to blame. There shouldn't be lessons. We have set-plays in the Championship against some teams even more dangerous than this level. The amount of 6ft whatever guys. You can't switch off."