I would respond that this is the Admission of the opposing party (Dealer) on either of two grounds:
A) Middle Man is a co-consporator. The fact that Dealer showed up in response to Middle Man's call has established the existence of the conspiracy.
B) Adopted admission. Dealer is accused of wrongdoing and fails to deny it.
END OF CLASS. If you have any questions, e-mail me at firstname.lastname@example.org.