Here's one to start you off:
If the real world worked like that, well we'd probably have a rather different value system. If killing someone meant they had to walk back for a couple minutes and caused them no permanent harm at all, I imagine it wouldn't be such a big deal.
...which is why people that actually believe in the death/resurrection teachings of their religions are so very, very dangerous.
Mathematicians stand on each other's shoulders. -- Gauss