Real Betis manager Pepe Mel was "bothered" with the decision to award Barcelona a controversial penalty in the Blaugrana's 4-0 defeat of his side on Wednesday at the Camp Nou.
Barcelona were given penalty when Lionel Messi collided with Betis goalkeeper Antonio Adan in the box as the Betis man cleanly punched away a dangerous Ivan Rakitic cross.
Neymar's subsequent shot from the spot hit the bar and bounced back into play, only to end up in the the back of the net from Westermann's attempted clearance.
"We were controlling the game pretty well," Mel said after the game. "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."