Comment # 1 on bug 1215845 from Stefan Dirsch

Hmm. Killing it once should not terminate the display manager. Could you please
check this behaviour with a displaymanager like xdm or gdm? 

I know that these are adjusted to terminate themselves if X crashes 3 times in
a row in a short amount of time. So you have a chance to get into the system on
Linux console. But not after killing X once ...