Is Theo The Balkan really dead?

All we saw was Suzanne pull a barber's razor out of her pocket. Who can say that she really killed him? When she told Sonny & Brenda that Theo was dead, she never said,"If you don't believe me, here is a map of the place where I left his body. Sonny can go send someone he trusts to investigate (Either Max or Dante or Lucky). And by the way, who was the mystery person she was talking to on her cell phone about 2 days after she gave Lucian back to Brenda? I think it was Theo and he's not really dead. What do you think?