Do you know that to be FACT? Just asking as far as I was aware nothing had been released to say this. Just because a payment was made doesn't mean that he was dismissed.
If he had simply resigned why did Lerner agree to pay out before it went to a tribunal?
Employment tribunal's can be costly matters for both parties. Unlike other civil cases, employment law means that the losing party is not responsible for the other side's costs and therefore it is sometimes more cost effective to settle pre tribunal. Plus he may have to been owed certain payments, bonuses, etc. Without knowing the full details of MON's contract and the full details of the settlment it is impossible to state either way whether he was dismissed or not.
If he was owed bonuses etc. why weren't they paid out when he left the club? Why wait until it's about to go to tribunal to settle? If he bottled it and resigned despite the backing of the owner then surely Lerner wouldn't have a case to answer. You're right, no one really knows what went on because of the confidentiality agreement which was seemingly signed, but to me it looks like he was effectively forced out, rather than being sacked per se.
In answer to your question, if you owed one of your employees say £3m in bonus, only for the stroppy little clearing in the woods to piss off 5 days before the start of a 10 month project you were paying him for, leaving you in the shit.... you may be slightly disinclined to pay him the bonus.