Barcelona coach Tito Vilanova was left frustrated by Gerard Pique's red card as his side lost for the first time in La Liga this season.
The Spanish international was handed a second booking against Real Sociedad as the league leaders surrendered a two-goal lead and their 19-match unbeaten streak to lose 3-2.
"Even if his (Pique's) sending-off was for a clear foul, there must have been 200 other cases similar to his tonight," Vilanova said.
"I don't have to add more.
"At half-time, I told Pique to be careful, as his next foul would most likely result in a second caution."
But the Barcelona boss also praised Philippe Montanier's Sociedad, who have not lost at home to his side in the past three seasons.
"Credit to Real Sociedad," he said.
"Their win is more due to their merit, rather than us not playing well. I have nothing to reproach the players for."
Veteran defender Carlos Puyol lamented Barcelona's first league loss of the season as did midfielder Xavi, but both admitted it was bound to happen at some stage.
"We should have scored more in the first half, but even if we had a 3-0 lead, it would not have been over, they have a great team," Puyol said.
"It's a pity, we could have gone up with (Lionel) Messi's shot against the post in the first half," Xavi said.
"The loss had to happen one day though, let's move on."
Messi, too, said the defeat was not entirely unexpected, but added that the side must now rebound with a win in the Cope del Rey.
"Losing a game had to come at some point. We have to pick ourselves up immediately because of the cup match coming up," he said.
Despite the loss, Barcelona still lie top of La Liga, 11 points ahead of second-placed Atletico Madrid.
The Camp Nou outfit travel to Malaga in midweek for their Copa del Rey quarter-final.