The deal was that he would get the bonus as long as he commuted to remain manager beyond the summer (defined as 31st August)
He supposedly has a run-in with the players on the 12th August.
On 13th August he asks for early payment of his bonus as he needs the money urgently to secure some property for his kids.
Then on 14th August he resigns.
No property was ever purchased. It was as dodgy as f***.
In normal jobs your only eligible for your bonus if you're still employed by the company on that date. Presumably why he lied to get it early.