In my opinion and based upon the very questionable appointment of Richard Masters , the corruption began very clearly at that stage.
US owned clubs contrived to ensure a beneficial treatment for their clubs , namely Liverpool,.rags, gooners and perennial losers spurs, to the detriment of other members of the PL.
That corruption has been extended firstly by the charges levelled against City because they threatened the status quo, followed by their enforced restrictions on Newcastle also viewed as a financial threat.
When those efforts failed, the PL management body ,lead by Masters, together with a cabal of US owned clubs have consorted to control and influence their authority and influence for their sole benefit over the remaining members of the PL.
None of the above has happened by accident, and controlling PGMOL is just a further extension of that operation.
The whole thing stinks of greed and corruption in plain site.