Jordi Alba and referee Antonio Mateu Lahoz had both "forgotten" about the Barcelona defender's first yellow card prior to his dismissal against Espanyol on Saturday.
Barcelona were held to a 1-1 draw by their Catalan rivals on what was a bittersweet day for Alba, who became only the 12th different player to make 300 LaLiga appearances for the club.
Alba's landmark outing was marred as the left-back received two yellow cards in the space of five minutes after Espanyol's leveller, with Lahoz losing control of the latter stages.
Lahoz, who was in charge of Argentina's fiery World Cup quarter-final clash with the Netherlands earlier this month, also sent off Vinicius Souza, while only a VAR review saved Leandro Cabrera after he was initially shown a red card for a stamp on Robert Lewandowski.
Alba will now serve a one-match suspension, meaning he will miss Barca's clash with Atletico Madrid at Civitas Metropolitano on January 8.
The Spain international revealed he received his second yellow card after voicing his frustration at a challenge involving Andreas Christensen and Joselu, whose penalty cancelled out Marcos Alonso's earlier header at Camp Nou.
"I did not understand the expulsion and I told him so," Alba said, in quotes carried by Mundo Deportivo. "I went to Mateu to tell him that Joselu had made [Christensen's] bed, nothing more.
"He thought it was the first yellow, and he showed me the second. For me, it is not even a card.
"I am aware that sometimes I make mistakes and protest too much because I am very impulsive, and I have to correct this aspect, but this time, it was not the case."
Sergi Roberto, who wore the captain's armband during Saturday's derby, concurred, telling Movistar: "Alba had forgotten his first card. We were all a little surprised."
Although Barca returned to the top of LaLiga on goal difference, they were punished for not converting their superiority into maximum points, having enjoyed over three quarters of the possession and registered 21 shots on goal.
"In the second half, we wanted to go for the second goal and to have the game more controlled," Sergi Roberto added.
"The game stopped a lot with the expulsions, the cards, and then we were not able to play our way anymore."