Episode #3.6 - S3-E6
Factual error: Humphrey and the rest of the crew arrive on the murder scene, where Fidel is taking pictures of the body. With the knife fully planted inside the victim and pictures still to be taken, Fidel is already able to say that the knife has been wiped clean of prints; it's impossible that he could have already done such an assessment at that point.
Answer: Most likely they had only tropical exotic drinks, he wanted an old fashioned English beer.