I do not know how it was supposed to work in EA's time, but I find no better way lobby creation can not fail, but at same time letting it to succeed while old team members are still in match, would cause problem, and leader can not leave the group before lobby is created. So the solution right now is that "fake" lobby is created, and destroyed instantly, then the party is informed that the member leave the group, so the "fake" lobby blink on the screen, and group is leaved, so he needs to create lobby twice in that case.