I too, have the issue where when they are dead, it keeps trying to make them dead, and they just slide around
I copied the debug log report

Theocalpos set dead while already dead.
UnityEngine.StackTraceUtility:ExtractStackTrace ()
Verse.Log:Error (string)
(wrapper dynamic-method) Verse.Pawn_HealthTracker:Verse.Pawn_HealthTracker.SetDead_Patch2 (Verse.Pawn_HealthTracker)
(wrapper dynamic-method) Verse.Pawn:Verse.Pawn.Kill_Patch9 (Verse.Pawn,System.Nullable`1<Verse.DamageInfo>,Verse.Hediff)
Verse.Pawn_HealthTracker:PostApplyDamage (Verse.DamageInfo,single)
(wrapper dynamic-method) Verse.Pawn:Verse.Pawn.PostApplyDamage_Patch1 (Verse.Pawn,Verse.DamageInfo,single)
(wrapper dynamic-method) Verse.Thing:Verse.Thing.TakeDamage_Patch3 (Verse.Thing,Verse.DamageInfo)
VFECore.ExpandableProjectile:Impact (Verse.Thing)
VFECore.GaussProjectile:DoDamage (Verse.IntVec3)
VFECore.ExpandableProjectile:Tick ()
Verse.TickList:Tick ()
(wrapper dynamic-method) Verse.TickManager:Verse.TickManager.DoSingleTick_Patch4 (Verse.TickManager)
Verse.TickManager:TickManagerUpdate ()
(wrapper dynamic-method) Verse.Game:Verse.Game.UpdatePlay_Patch2 (Verse.Game)
Verse.Root_Play:Update ()