Episode #4.8 - S4-E8
Plot hole: For things to go the way Goodman describes them, Dwayne and JP must have not heard in the deserted courtroom building the noise of the glass of the fire alarm button being shattered in the corridor just outside their position. It's an impossibility. (00:18:00)
Episode #4.8 - S4-E8
Plot hole: The way the murder happened (where was the gun shot from?) is entirely unknown for the first couple of days, not even a hint - it seems the investigators don't care at all about it, which is quite silly per se. More importantly though, knowing so little about the way the shooting happened would have at the very least prompted an analysis of the shirt to check the entry wound and any residual. During that sort of test the 'other substance' used in the trick would have been easily discovered (visually it is radically different up close and drying out), exposing the culprit.
Answer: Most likely they had only tropical exotic drinks, he wanted an old fashioned English beer.