If you had said that atheists believe there is no life after death, AND they have no ethical or moral priciples, therefore they can rape and pillage, you'd have made your point.
Logically, the evolutionist/theist can still jettison their theism for the underline evolutionary justification at any time. The creationist has no such recourse.
On the other hand, as you indicated, the atheist/evolutionist has no construct to hold onto morality at any time. Thus in discussing with my daughter whether she could marry an evolutionist, I said that even after marriage, he could justify leaving her at any time for a prettier or healthier woman; her holding on to him would be dependent on her functionality and desirability at any given time.
The logical implications of evolution on both science and morality are evident when you look at the mechanisms chosen. In this case, the mechanisms are death. Moses, said "Choose Life". So the question of which you choose is logical.