I was killing all item entities with the following command: /kill @e[type=Item], when a tile entity with the name item.tile.notGate. The first item that comes to mind for this is the redstone torch, but I am pretty (not 100%, but pretty) sure that I had no redstone torches as item entities. Also, I have used the /kill @e[type=Item] command many a time before, and never seen it up until now. Unable to reproduce.

I had to mark it as a 1.8.9 bug, but the version I was in was 1.8. I was using Forge, so I was in 1.8. Here are a list of mods that were installed:

[1.8]bspkrsCore-universal-7.01
[1.8]ArmorStatusHUD-client-1.29
[1.8]StatusEffectHUD-client-1.27
[1.8]DirectionHUD-client-1.24
worldedit-forge-mc1.8-6.1