Because the Mayor, City Council and Police Chief wanted to be seen as in favor of diversity and wanted a Somali cop, no matter the outcome.
That is exactly it. The Dem female Mayor of Minneapolis at that time wanted to have a Somali police officer, so that she could look like a good progressive. So Noor was rushed through, even though he was unqualified. Another Affirmative Action case in which the politician can feel good about herself, while somebody else in the general public has to pay the price.