Eccentric entrepreneur and Dallas Mavericks owner Mark Cuban took to Twitter following his team’s 127-125 loss to the Golden State Warriors on Wednesday night, calling out the “worst officiating mistake in the history of the NBA” and planning to file a protest of the game’s result.

Golden State was given possession on an inbound play with 1:59 left in the third quarter, and with no Dallas player in sight, Kevon Looney threw down an uncontested dunk to give the Warriors a 90-87 lead.

After the two-point loss, Cuban tweeted that the Mavericks should have been awarded possession (opens in new tab), only for the referees to change the call without notifying his team during the timeout. Referee Sean Wright said that the officials had signaled possession to Golden State (opens in new tab), then signaled a timeout for Dallas.

Similar confusion over a possession and timeout call unfolded at a Bay Area high school basketball game between Riordan and Serra in January.

Only six games have been successfully protested in NBA history (opens in new tab), and only one of those successful protests has been recorded in the last 40 years. If the protest is successful, the game would be replayed from the point of the call, with Dallas taking possession down 88-87 with 1:59 left in the third.

The protest must be accompanied by a $10,000 fee, which would be refunded if the NBA upholds the protest. But $10,000 is chump change to Cuban; Bloomberg estimates the (opens in new tab)Shark Tank (opens in new tab) star’s net worth at $6.4 billion (opens in new tab).