Pepe Mel was left perplexed at the awarding of a penalty for Barcelona as Real Betis slipped to a 4-0 defeat at Camp Nou on Wednesday.
With the game goalless after 28 minutes Betis were more than holding their own against Luis Enrique's side, but their challenge became tougher when Barca were awarded a controversial spot-kick.
As a cross arrowed in towards Lionel Messi in the area, goalkeeper Adan punched it clear but was penalised by referee Inaki Bikandi for colliding with the Barca striker.
Even though Neymar hit the crossbar with the resulting penalty, Heiko Westermann turned the rebound into his own net under pressure from Ivan Rakitic and Luis Suarez.
Betis quickly crumbled as Barca turned on the style, but Mel - who was sent to the stands for protesting the penalty decision - laid the blame for their defeat firmly at the feet of official.
"We were controlling the game pretty well," he said. "When the penalty came after half an hour the only chance had fallen to Dani Ceballos.
"All my life I played centre forward and I never got a penalty in that situation.
"After that everything changed. It bothered me that such a decision takes us out of the game.
"I do not know what he saw, it was a very strange penalty. They are bad decisions but we must accept them.
"I do not know why I was sent to the stands. I have not disrespected [the referee] or said anything, not even when he expelled me."