I think retrespectively Atletico can pat themselves on the back for getting out of this with 10 men and a draw. In general however they should really win such a game. They are the better team, they have better players and they are more experienced on this level. They are able to win this tie early, but now they are still in danger of going out if they play like this again and Arsenal gets luckier with the finishing. It's a relatively neutral result for both teams. Atleti has the home advantage now, but other than that I think they didn't need to play for a draw at the Emirates.