>In essence the defendant shouldn't be rewarded for the prosecutorial misconduct.

no, that's not what was being argued. The decision uses the established precedent that defendant is to be "rewarded" in case of "outrageous or conscience shocking" prosecutorial misconduct. Kamala didn't argue against that. What, in the words of the judges listening to her, she argued is:

" On appeal, however, the People dispute that Murray’s misconduct was outrageous or conscience shocking in a constitutional sense, as it was not physically brutal.

...

According to the People, this language stands for the proposition that misconduct must be “brutal” in order to shock the conscience and support a sanction of dismissal. "

May be you think that the judges misunderstood the arguments presented by the "People" ? :)