Just as I suspected. There was a third person in the room. Before you came to, you were partially covered with a blanket. I assume the killer believed they had taken care of the both of you, or simply did not feel up to finishing the job.

[What a sloppy murderer, either way...]

He may have panicked and used whatever abilities he had to protect you at the moment. He may not have known Elizabeth was in danger. [A nod.] Alice, did you know he was a medical officer, before?