Los Che were leading 1-0 at the Jose Zorrilla when winger Omar Ramos was felled by Aly Cisshoko in the 64th minute, and the officials saw fit to dismiss the Frenchman and award a spot kick, which Victor Perez converted.
“We are not happy with the result because we wanted to win,” the 41-year-old told reporters. "It was not a penalty. Omar hit the ground when he saw that Valencia were going to regain the ball.
“The match totally changed with Cissokho’s red card, but for the final eight minutes, we still had control of it. Overall the game was even, and they had not had many chances.
“We were organised, but lacked the freshness to subdue Valladolid.”
However, Valladolid boss Miroslav Dukic is adamant that the official's decision was the right one.
“The penalty seemed clear to me, while both Omar and Alberto Bueno did well moving between the lines," the Serb commented.
The result leaves Valencia in ninth place in La Liga, 13 points behind table-toppers Barcelona.