1st point
Twente won the league that year indeed and did mc claren won it last year? no he actually gave the championship away
I think ajax was around a 14 game winning streak last year which sealed the deal. Conte did well with juve and before that he proofed nothing too. Don't forget that it is de Boer his first job as a manager. And I do believe Barca was interest last year to have him as their manager.
2th point
I believe pirlo played at milan at that time
and buffon was injured or played good. just cos del neri was dumb to play with melo and marchisio as lm

was more the problem we finished 7th,
and for your interest
re watch
manchester united vs ajax febuary 2012
and milan - ajax and specially the game before that game in the eredivisie
nec - ajax december 2010
then you will see what de Boer did with ajax