According to Mundo Deportivo, Pique responded on social media to a user who criticized Barcelona's way of winning.

Pique defended Barcelona on social media by replying to a user who criticized the way the club achieved victories.
Pique said on his social media account: "Barcelona only has one way to win, and that is by playing attractive football. We have played very beautiful football, won many league titles, many Champions League trophies, and many trebles. So you always bring up referees as an issue. Let me remind you that in the 1998 Champions League final between Juventus and Real Madrid, the goal scored by Mijatovic was not valid."
"There were also the two finals between Atletico Madrid and Real Madrid, and Ramos' goal in 2016 was also offside. So refereeing errors happen quite often. Looking at history, referees have generally been slightly more favorable toward Real Madrid. Apart from that, I hope everything is well with you. Have a good Monday."
In the 36th minute of the 2014 Lisbon final, Diego Godin gave Atletico Madrid a 1-0 lead. Atletico held that advantage for almost the entire match and remained ahead until stoppage time. In the well-known final moments, Ramos scored a header to equalize and send the game into extra time. Real Madrid then won 4-1 with goals from Bale, Marcelo and Cristiano Ronaldo.
Two years later, the two teams met again in the final. Ramos scored again in the 15th minute, although there was an offside controversy at the time. Shortly after the second half began, Atletico Madrid had a great chance to equalize, but Griezmann's penalty hit the crossbar. Atletico continued attacking, and Carrasco made it 1-1 in the 79th minute. Neither side scored in extra time, and the match went to a penalty shootout, where Atletico Madrid lost to Real Madrid.