Factual error: Noticed this watching season 2, and I assume it was also the case in season 1. The entrance of the Miramar Playa has flags from various countries flying. One of them is the Canadian flag with the maple leaf. Wrong flag. In that period the Canadian flag was the "Red Ensign", or "Dominion Flag." The maple leaf flag wasn't introduced until 1965.
Who's the Horse and Who's the Rider? - S1-E7
Continuity mistake: When Stevie is confronted by Danny on the beach, he's wearing a gold chain with a star of David. Different angles through the scene show him not wearing it. The different takes alternate between chain and no chain.
Character mistake: The doorman tells Ike that Jimmy Shoes and the prostitute left in a '55 Chevy, the car is a '56 Chevy.
Factual error: At the hotel, there are flags at the entrance of the lobby. There is a Canadian flag. The current flag is in that scene, but was only implemented in 1965.
Factual error: In some scenes there is a sunset over the beach. The sun doesn't set in the east over the beach in Miami.