If the default ingame NPCs 'Expire' then Death Kick fires out an error... Something to look at in a future push maybe:

Failed to call hook 'OnEntityDeath' on plugin 'DeathKick v1.0.0' (NullReferenceException: Object reference not set to an instance of an object)
  at Oxide.Plugins.DeathKick.ProcessDeath (Oxide.Core.Libraries.Covalence.IPlayer player, HitInfo hitInfo) [0x00014] in <3de0f473fd0246ec8fc6cfa70706ed90>:0 
  at Oxide.Plugins.DeathKick.OnEntityDeath (BasePlayer player, HitInfo hitInfo) [0x00000] in <3de0f473fd0246ec8fc6cfa70706ed90>:0 
  at Oxide.Plugins.DeathKick.DirectCallHook (System.String name, System.Object& ret, System.Object[] args) [0x0007e] in <3de0f473fd0246ec8fc6cfa70706ed90>:0 
  at Oxide.Plugins.CSharpPlugin.InvokeMethod (Oxide.Core.Plugins.HookMethod method, System.Object[] args) [0x00079] in <8a646463979e4a1d9c0e2f1298e9483f>:0 
  at Oxide.Core.Plugins.CSPlugin.OnCallHook (System.String name, System.Object[] args) [0x000d8] in <1fe782f4b27a43ae85d29ebb2d56c007>:0 
  at Oxide.Core.Plugins.Plugin.CallHook (System.String hook, System.Object[] args) [0x00060] in <1fe782f4b27a43ae85d29ebb2d56c007>:0 

Thanks for the report. It should be fixed in the latest version, otherwise please let me know.