Leverkusen wasn't any better side in that game, I wouldn't want to use the bias of the fact that they were able to put up very brilliant performance form the beginning of the season till this point to say that they were a better side in the finals and Atlanta was less deserving of the victory which can invariably be said that they were lucky. Leverkusen have been a good side throughout the Europa league games from the beginning to the point they got to the finals, Atlanta can be said to be lucky only at some stages of the Europa league games especially when they met Liverpool but with Leverkusen they were only a better side.
Obviously Leverkusen appeared like they didn't expect such loss at the finals of that game as they haven't experienced such since that season, it was their first time experiencing defeat that season an their reaction made it very obvious that they were actually experiencing it for the first time, and it was sad that the first time.they had to experience such was at the time they needed their wins the most.