Had Oliver known that, he might have brought along a vase with the flowers. Because he's thoughtful like that. But since he hadn't known that, no foul.
Oliver couldn't believe that. It just didn't make sense to him. "I can't understand why. You're one amazing woman, Z and you deserve to be treated as such." He wasn't attempting to smooth talk her -- he meant every word. Truth of the matter was, he cared about her.