Sevilla had gone down to ten men following the 58th-minute sending-off of Arouna Sangante, and Luis García Plaza was adamant the decision had been harsh.
"We're really struggling with these decisions. Sangante touches the ball, it's not a red, there's no interpretation needed. After touching the ball, what does the player do? He goes down, he touches the ball and he can't get out of the way, he can't disappear," the Sevilla boss said.
"This time everyone agrees it's not a red — everyone on the pitch who spoke to me."
García Plaza revealed the referee had explained the sending-off but not the two goals.
"He hasn't explained the goals to me. He did come over because when he showed me the yellow card, he explained the dismissal. But the goals, I don't know, I haven't seen them," he said.
Despite the numerical disadvantage, the Sevilla boss felt his side had more than held their own.
"I think it was a really rich game. They got the better of us at the start, but after the first quarter of an hour we adjusted really well, and I think we had the game under control," García Plaza said. "With ten men I think we played a brilliant game, because it's not just the goal, it's that we got in front of their goalkeeper. The goal they scored against us was a strange one — we can't defend the box like that in the last play, and it's a mistake we need to correct."
Espanyol boss Manolo González, meanwhile, was left frustrated by the disallowed opener that had put his side ahead through Omar El Hilali.
"Nobody really understands why they've ruled it out," González said. "There comes a point where we don't really know what is or isn't offside."
He explained match officials had ruled the goal out because Marcos Fernández "was in the trajectory," adding that similar calls seemed to be interpreted differently "from one week to the next."
González felt the disallowed goal had affected his side more than conceding to Aaron Stassin in the 85th minute.
"Yes, because it's a move of great merit from Javi Hernández, who delivers a really good cross, and Omar gets on the end of it well. The game turns in your favour with the 1-0 and they have to open up," he said.
On the red card, González was unequivocal.
"It's clear. However much he touches the ball, he touches the player, because otherwise Roberto Fernández is left clean through on goal," he said. Marcos Fernández, brought on before the red card was shown, grabbed the equaliser deep into stoppage time.