It would be embarrassing as the club released a statement saying he was released by mutual consent. If he turned around and said he had been sacked he'd be calling his employers liars.
Come on Drogs, you are a sensible fellow, what do think would happen if Mourinho had said he was fired by Abramovich and took a £10m payoff not to speak about it in the media when he left and let the club say it was mutual? The media **** storm would have lasted months, harming his preparation for the new season. That's not something Mourinho would ever countenance happening - he'd lie through his back teeth rather than risk anything coming out which could damage the team. So would SAF, and any half decent manager.
I can understand you're annoyance at shwan and
Sisu's attempts to present it as a black and white (
unfortunate turn of phrase?

) issue. Ultimately, as with any footballing issue, there's never any concrete evidence as the discussions always happen behind closed doors, and the compensation packages agreed almost always have some form of confidentiality requirement.
But are you seriously telling me you genuinely believe Mourinho was happy to leave when he did, and was in full agreement when the club suggested he step down as manager? Particularly given his comments before and after he left about having to be fired to leave and that Chelsea shouldn't have decided to change their manager?