First to bet after turn, bets pot ($1300) in PLO. One folds, last player takes a long time to call. Bettor immediately hits the table with his fist, nothing verbal.
After the river, the bettor, without hesitation, says and pushes all-in. The dealer says that the hand slap on the table pre-river was a Check-in-the-Dark.
Bettor almost always verbalized his calls/raises, and had never hit the table like that previously. His explanation was that the caller had taken a long time to call, his slap meant: now let's play/gamble. Nothing was said.
Floor agreed with the dealer. Other players at the table did not.