I am sorry that happened to you unfortunately you fell victim to the unorganized mess that is FLL. No excuse for the agent to do that but I bet you he was trying to board three flights at the same time and didn't want a delay on him. Same thing happened last week we were about to leave three including a company captain with seats open. Luckily the captain called us and we waited and took everyone. Next time grab a pilot on the way downstairs and we will gladly try to let the crew know since all the planes are parked near the same gates.