Runtime fixes, tweaks.

code/modules/mob/living/carbon/human/life.dm

@@ -1022,7 +1022,7 @@
 
 		for(var/image/hud in client.images)
 			if(copytext(hud.icon_state,1,4) == "hud") //ugly, but icon comparison is worse, I believe
-				del(hud)
+				client.images.Remove(hud)
 
 		client.screen.Remove(global_hud.blurry, global_hud.druggy, global_hud.vimpaired, global_hud.darkMask)
 

code/modules/mob/living/silicon/robot/life.dm

@@ -160,7 +160,7 @@
 
 	for(var/image/hud in client.images)  //COPIED FROM the human handle_regular_hud_updates() proc
 		if(copytext(hud.icon_state,1,4) == "hud") //ugly, but icon comparison is worse, I believe
-			del(hud)
+			client.images.Remove(hud)
 
 	var/obj/item/borg/sight/hud/hud = (locate(/obj/item/borg/sight/hud) in src)
 	if(hud && hud.hud)	hud.hud.process_hud(src)

code/modules/mob/living/simple_animal/hostile/hostile.dm

@@ -40,7 +40,7 @@
 					T = L
 					break
 
-		if(istype(A, /obj/mecha))
+		else if(istype(A, /obj/mecha)) // Our line of sight stuff was already done in ListTargets().
 			var/obj/mecha/M = A
 			if (M.occupant)
 				stance = HOSTILE_STANCE_ATTACK