There is no excuse for Barcelona drawing to Rayo Vallecano, the home club were so good on the match day. They played so well and exceeded Barcelona’s expectations, defended so well and deserved to get atleast a point from the game. Probably Barcelona underestimated Rayo Vallecano going into the game and were stunned by how well they played.
There is no obligation that small teams always play badly. I will not blame Barcelona and say that they played badly, but the opponent team Rayo Vallecano played much better than Barcelona and our expectations. I even think that they were the best to win the match. Barcelona were fortunate enough to score a goal and end the game in a draw through a penalty, which was probably a bad decision by the referee. Such unexpected results are common in the season and even weak teams can surprise with unexpected results, so evaluating every team equally can bring positive results. Small teams are also playing to improve themselves.