The visitors trailed 16-6 at the break and had no reply to their hosts' power after the turnaround despite the numerical advantage gained when Bousquet was dismissed.
Veivers said: "I was disappointed with the cheap shot on the little half-back who got took out by the big number 21 (Bousquet), it was a very cheap shot. I thought it was outlawed in this game and the referee dealt with it correctly."
He added: "It had a big bearing on the game for us, having four forwards on the bench detracted from the way we wanted to play.
"After that I cannot subtract from the effort the players put in, the lack of game awareness and game sense was overwhelming - five times we kicked off the sideline."
Veivers laid into his side as he spoke about the same mistakes being repeated that appeared in the defeat to Wigan last weekend.
"It's two weeks in a row that we're talking about the same mistakes, it's got to sink in shortly," he added. "Possibly that is down to inexperience within the squad but you cannot excuse the amount of dropped balls we came up with tonight, the amount of cheap penalties we conceded and how we finished our sets, especially in the second half."
Catalan coach Laurent Frayssinous was delighted his side were able to win despite having 12 men for 77 minutes of the game.
"It was a good win for us, and I'm especially pleased with the defensive effort of the guys," he said. "For us to only concede one try with having a man less for most of the game speaks volumes about the character of the team."
Frayssinous went on to speak about the incident in the third minute that saw Bousquet sent from the field, adding: "We won't tell Julian what he has done is wrong. I don't think it is a late challenge, but just perhaps the timing is out a little from Julian."