And indeed, here is the corresponding Xorg.0.log showing what was going on in those vital five seconds before the assassination. Indeed apparently the clock started ticking even before X was logging things. You know, I bet the best thing to do would not be to create such RACE CONDITIONS at all, and instead have it be a not default option in /etc/default/nodm for those who want it.
Xorg.0.log.old.gz
Description: Xorg.0.log
However I have been wrong in the past.

