I'm sure thats not allowed you know, they can't just start an exam an hour early because they feel like it. All exams should start at the same time across the whole country otherwise if time differences become involved cheating becomes a possibility.
Someone could have come out of your exam after they finished at 2 o clock, tel someone else all the answers, and then they could go in half an hour late to their exam at around 2 o clock and get away with all the answers.