Football matches aren't won by statistics as there're different strategy to win a matches. A team might decide to sit deep to defend and counter attack their opponents when the opportunity presents itself resulting to them most likely winning the game. Atl Madrid are known for doing exactly that. That Liverpool dominated most stats is mostly due to the fact Atl Madrid allowed them to.
And Liverpool are also not a team that dominates when it comes to possession, they are mostly an all out attack team, relying mostly on plenty of crosses. Atheletio made them dominate possession just as you said, they(Athletico)love to sit back, tighten up their defense and are decisive in attack, this presented a field day for Liverpool to dominate the possession and boss the game.To be fair to Liverpool, they should have won the game, they were the better team and should have scored more goals than Athletico, but in football a second can change anything, sadly Adrian turned out to be the villain at the end of the day as Diego simeone and his men progressed. Liverpool have only the EPL to win now, not as successful as they would have wanted I'm sure.
