Taking a step back from the Halsey comments and the rights and wrongs of the Aguero incident, it is just pure logic that the refs are corrupt.
A quick look /google at the history of corruption in sport shows a strong link between sports that are awash with money and organised criminal gambling. Surely the amount of dosh swilling round the EPL will attract the attention of these criminals?
Again logic would suggest that the weakness in the league for criminals to exploit is not the players who already earn a fortune, or the managers who have to keep winning to stay employed. The ideal candidates for bribary, intimidation ect are the refs. They are paid a comparative pittance and have the ability to steer the course of the game, safe in the knowledge that even ridiculous decisions or oversights will be put down to human error, or subjectivity which is part of the game.
They can also depend on being defended to the hilt in this respect by the FA and their own organisation.
Just ask yourself the question, if you were a gangster interested in influencing the outcome of premier league matches who would you lean on?
For me its simply a question of if you believe there is corruption. If there is then it has to be the refs.