Kerbal Space Program

I have two things to do on mission:
1) dock on or around body
2) Return to Kerbin from surface of body

I did these with seperate vessels but only 1st is completed. Should returned vessel from surface be same which did docked, mission describtion doesn't say it has to be. Or is this just broken mission.
It should say it more clearly or be more tolerant. Humans did go to moon surface and returned from there, but if this was kerbal then we didn't return from surface of moon because we left our lander behind.