Other mistake: The police force is searching the room of the deceased at the beginning of their investigation, Humphrey stands in front of a map of Saint Marie with the exclusion zones. The map though shows an island upside down compared to the map you could see in Episode 7 of season 2. (00:10:10)
Other mistake: In the bank statement that Dwayne hands to the DI, there are cash withdrawals "from the past three months", with the past three months being January, February and...February, again. (00:20:30)
Other mistake: Torey Martin says that he had an accident 5 months before, but the car crash evaluation is signed 31/07/2016. Not only it was a Sunday - unlikely day for the car shop to be working -, but that would put the events of the episode on January, contradicting the bank statements and what was established in previous episodes.
Other mistake: The police boat approaches the scenes of the crime coming in from the right, in a straight line, then in the proximity of the boat they turn around it, moving clockwise, passing in front of the bow and then to the left side. When they review the readings though, the icons show a completely different story, as if the police boat approached from behind and they boarded docking right at the stern. (00:04:40 - 00:08:00)
Other mistake: Days in the series seem sometime to go on for unusually long amounts of time. In this episode, there's the exact opposite; the murder happens at 10 AM (which already seems awfully late for the opening of an election), the police obviously are called right away, Jack and Florence go to the station to discuss the case, and then all of a sudden it's a wrap when Dwayne and JP get back there with their findings. Unless they have searched the businessman's residence for over 6 hours while Jack and Florence have been doing next to nothing at the station, it makes no sense.
Answer: Most likely they had only tropical exotic drinks, he wanted an old fashioned English beer.