What would Dylan do if he knew Lionel was actually set up by her?
In any case, he couldn't get to the bottom of the matter.
The aphrodisiac she put in Lionel's wine was bought from the black market. It was usually used by playboys on those girls who enjoyed themselves alone in bars. In order to avoid legal liability, what people looked like after swallowing this kind of aphrodisiac was the same as when they were drunk. The medicine would soon take effect, but it would also wear off in about half an hour. Nothing could be found in the sufferer's body even if she or he went to the police and got an examination in the hospital.
Lionel was knocked out by Dylan after the medicine got the full effect that night. It must be more than half an hour when he was found and taken to the hospital. It was hard to find out what he had taken when he felt something wrong and asked for an examination.