Gamerule keepInventory sometimes fails to work

Occasionally when a person has died with the keepInventory gamerule on, they lose their stuff, specifically in the nether. It happened to me once and my brothers twice

What I expected to happen was...:
to die and not lose my stuff

What actually happened was...:
we died and lost our stuff

Steps to Reproduce:
1. turn keepInventory gamerule on in a server world
2. die in the nether until you lose your stuff
3. ...