He's having sex with... (spoilers naturally)
the subject? The doctor is having sex with the patient? Since he doesn't actually answer the accusation and it never really shows anything it was hard to tell if that was what was going on but if there is even the accusation then what is the point of continuing with the experiment since it will be dicredited anyway?
Indeed, it seemed that jealousy on the part of the client was the motivation for the climactic catastophy thus destroying any value of the entire adventure being evaluated from a scientific point of view.