It wasn't because Draco didn't believe Pansy could take care of herself that he was bothered by what had happened. No, part of what worried him was the nagging worry that her attack had been a part of the rash of violence against people that Death Eaters cared about - a group of people out there, somewhere, using their own tactics against him. He or Fletcher, or possibly both, would be the reason for the attack, if that was the case.
And of course, he was afraid for her, not wanting her to undergo the same transformation that he had. Perhaps somewhat selfishly, since he wanted to be able to find relief from that part of his life when he was here, with her, but also for her sake.
He didn't have words, either, and so when her lips pressed against his, he didn't object. His arms tightened around her and he kissed her, lingering over it and deepening it slowly, letting the effect of the kiss soothe his nerves, and hopefully hers as well.