The modus of these cheaters is that they paired battlecocks during a fight, they already know which cock will win and the management of the betting site will notice this as there is a spike in the betting, meaning that during the fight of the "paired cocks" millions of pesos was placed to the supposed to be the winning cock. Hard to explain and also hard to get if you are not into cockfighting.
So the odds are supposed to be 1:1 for all fights? That would explain why they can't shift the odds to offset the incoming bets.
I've never actually bet on a cockfight but I remember seeing "e-sabong" as its own section tucked away on a few different gambling apps; usually you just pick Red or Blue and hope for the best... about as random as a coin flip, or so it seems...