Dallas Mavericks owner Mark Cuban has taken to Twitter to express his dismay at an officiating call during a regular season game against the Golden State Warriors.

According to Cuban, the referee changed a call during a timeout in Wednesday’s game, switching possession from the Mavericks to the Warriors. Cuban said that the officials did not communicate any reasoning for the change. The Mavericks had been lined up at the far end of the court, believing it was their possession. The Warriors were then given the ball and Kevon Looney was able to score a wide open basket with no Mavs defenders in sight.

Mavericks went on to lose the fixture on a 125-127 score line

Cuban said that it could have proven a significant turning point in what turned out to be just a two-point game, which the Mavericks went on to lose, 125-127. The billionaire labeled the decision the “worst officiating non call mistake possibly in the history of the NBA.” The Mavericks are reportedly planning to formally protest the decision.

Warriors head coach Steve Kerr does not agree with Cuban’s view on the matter, believing that it was pretty clear that it was a Warriors ball. Crew chief Sean Wright also provided an explanation after the game, saying that the original signal was for a Warriors ball and that a second signal indicated that the Mavericks had a mandatory timeout.