Miami Heat head coach Erik Spoelstra admitted that his own “horrendous mistake” cost the team in its 123-121 defeat to the Detroit Pistons in the NBA Cup on Tuesday.

That last game was particularly interesting because it involved one of the greatest coaches of this generation making an incredibly uncharacteristic mistake at the worst possible time. With the game tied at the end of the extra period, Erik Spoelstra called a timeout … even though the Heat didn’t have any.

With Jimmy Butler missing a second game in a row with a sprained ankle, The Pistons’ bench made a difference, particularly Isaiah Stewart (13 points, 10 rebounds and a big put-back dunk late) and Malik Beasley, who hit four threes on a 19-point night.

With the game tied in overtime, Miami tried calling a timeout. There was just one problem: They didn’t have one available.

Malik Beasley made a tiebreaking free throw with 1.1 seconds left in overtime after Miami was given a technical foul for calling a timeout when it had none left, and the Detroit Pistons edged the Heat 123-121 in an NBA Cup game on Tuesday night.