It's kind of a wired way of betting to me. I wonder what else they place bet on that sounds very wired. Well, in common sense if the body was so close to the prime Minister, he probably must have gotten a tip from someone on the inside about the election date. That would be the only way he had gotten it and made a bet which is cheating obviously. But it might be a mistake though as no one can actually tell if that's what happened. He might just be blamed falsely just because he works for the prime Minister. He might just be like every other gambling who would have won the bet on similar occasions but the condition of his work just gave him another issue to fight over.
He might not heard of the elections date before he predicted yours, is close to prime minister, that doesn't mean that he has all necessary information of everything that has to do with elections date, their is something we called brain wave and brain magnet, you may be thinking some else within environment you find yourself and due to its something that you have in mind to say somewhere else, but due to brain wave can make another person to have same thought, two things are involved there, it neither he has heard the information of the date or brain wave magnet it for he to make such bet, but science proved to us that two persons in same on environment can imagine one particular thing.