Continuity mistake: Officer Dwayne Myers pulls the shades from the sock; he is holding them in a different way between shot and reverse (fingers on the lens vs fingers on the hinge). (00:12:00)
Character mistake: Dwayne tells Jack on the crime scene that the victim (who had two aces, with one ace on the board) he had "three of a kind or as the pros say, trips." Pros don't say "trips" to that though, since "trips" happens when two cards matching one you have in hand are on the table. Holding the pair makes it a "set." (00:06:25)
Plot hole: There is simply no way that the cheating presented in the episode, with the player reaching in his pocket to mark the cards, consistently for over 5 years (!), and wearing the same obvious prop, could go unnoticed, especially in official tournaments with millionaire prizes, on camera even.
Continuity mistake: During the questioning of "professor" Eugene Sutton, his hand is flat on the table in front views, with the side down in the reverse angle. (00:34:00)
Continuity mistake: Office scene with the poison being revealed. Dwayne in his snazzy detective suit interjects that you have to know the right, or wrong people to get a hold of it. In the wider shot (whole room in frame) Danny John-Jules' left hand covers the cuff of his blue shirt, while in the closer angle the shirt is perfectly visible. (00:13:50)
Continuity mistake: After mentioning the Dutch poker player, JP waves around the calling card of the taxi driver. He holds it vertically when seen from behind, horizontally in the front shot. (00:27:50)
Other mistake: Meeting with the suspects for the first time, Jack is flipping through the brochure with the player profiles while "The prof" is saying that logistically speaking the murder is impossible. Jack looks down at a page, but the close-up shows a different one. (00:08:35)
Continuity mistake: During the denouement, the natural light on the poker table changes continuously between shots. (00:41:45)
Answer: Most likely they had only tropical exotic drinks, he wanted an old fashioned English beer.