Question is, how can gov officials gamble that big when their salary won’t even cover a fraction of it? Corruption? Loans? What do you think?
Without a single doubt, it's corruption. A gambler won't play his own money and blew up 300m PHP in cash if you are public official, you won't just waste your savings for gambling but it's different if it's not your money. You are not scared or afraid to lose it since it's your not money anyway, and I think we can't blame it up to gambling because whether there's gambling involve or not, a corrupt official will always be a corrupt officials. It's just sad that the money which should benefit the community got used for personal interested.
You are making a point here, no public or government official would, in his or her reasonable sense, take such a risk of burning such an amount of money if at all they earn up to that figure, because they know what it takes to get such an amount of money, but it's unfortunate that it is corruption in play and they burning such figures without feeling it. This is something that would create impact in their society if used that way for developing the society or put into the economy. It is really corruption in play, as nobody would make such a mistake of taking a loan to gamble on games they are not sure of winning.