He obviously still doesn't remember any of this--or almost anything about that night, for that matter. Needless to say he's still not sure what she's talking about in terms of "sharing blood", but he'll take her word for it.

At the thought a chill runs through him. When he'd been addicted to heroin while he was undercover, he'd always been careful to use sterile needles that he'd provided himself, for his own safety, and all the blood tests his doctor had done when he'd gotten clean had come back negative. But even though he knows she's safe, the thought that if he hadn't been careful he could have gotten not only himself infected, but someone else, someone who saved his life... It sends a chill down his spine. Not for the first time he realizes exactly how stupid his drug use had been, even if it had been necessary for his cover.

"That doesn't exactly sound...safe."