When under resistance effects above 5, /kill command does not work.

When a player is under the effects of resistance over level 5, the player becomes immune to all damage including the /kill command. This should not occur because even though the resistance gives invincibility, /kill is a server command and shouldn't not work.

What I thought would happen
Using /kill while under resistance 5 would kill me, because it is an operator server command and shouldn't be blocked.

What actually happened
My player made the animation of taking damage, my hearts blinked, and I made the damage noise, but I did not take damage and did not die. The dialogue "Ouch. That looked like that hurt." pops up.

Steps
Use /effect @p 11 10 5 in a world w/ cheats
Use /kill

I understand if this is not valid and "works as intended", but this is quite inconvenient at certain times when making custom maps.