I suspect you're right that the club wrote a draft, but, given it contains actual quotes from Sami, he will have approved it. There may well have been a financial incentive for him to do so, but nonetheless he will have ok'd it.
Sami's statement is classy. He had to go, but he's handled himself well over it so far. Good luck to him in the future, especially if he ends up managing a relegation-threatened Championship side soon, as we'll have a good chance of 3 much needed points when next we play them (cheap shot, I...