I understand this, indeed you are correct. However he was only in the slipstream as Kimi moved across to block him (legally) after the start/finish line. Kimi holds his line, Hamilton never gets past.
Yes but he did get past a direct result of cutting the corner, therefore he needs a penalty.
Nikki Lauda unequivocally condemned the penalty as unfair and opined that the stewards were nincompoops.