Bug when docking two crewed ships

I had a ship in orbit (transfer stage), and was launching a lander to dock with it, so that the whole assembly could then boost out for another planet. The ship had a crew of 1, and the lander had a crew of 2.

However, when I docked the two together, the guy in the transfer stage just seemed to vanish. Is this normal? Do I get him back when I decouple again?