Fixes a few runtimes

code/_onclick/item_attack.dm

@@ -58,7 +58,7 @@
 				else
 					return 1
 		var/obj/item/organ/external/O = M.get_organ(user.zone_selected)
-		if((is_sharp(src) || (isscrewdriver(src) && O.is_robotic())) && user.a_intent == INTENT_HELP)
+		if((is_sharp(src) || (isscrewdriver(src) && O?.is_robotic())) && user.a_intent == INTENT_HELP)
 			if(!attempt_initiate_surgery(src, M, user))
 				return FALSE
 			else

code/game/gamemodes/miniantags/bot_swarm/swarmer.dm

@@ -421,13 +421,13 @@
 	return FALSE
 
 /obj/structure/lattice/catwalk/swarmer_act(mob/living/simple_animal/hostile/swarmer/S)
-	. = ..()
 	var/turf/here = get_turf(src)
 	for(var/A in here.contents)
 		var/obj/structure/cable/C = A
 		if(istype(C))
 			to_chat(S, "<span class='warning'>Disrupting the power grid would bring no benefit to us. Aborting.</span>")
 			return FALSE
+	return ..()
 
 /obj/item/deactivated_swarmer/IntegrateAmount()
 	return 50

code/game/objects/items/weapons/handcuffs.dm

@@ -37,6 +37,9 @@
 	cuff(C, user)
 
 /obj/item/restraints/handcuffs/proc/cuff(mob/living/carbon/C, mob/user, remove_src = TRUE)
+	if(!istype(C)) // Shouldn't be able to cuff anything but carbons.
+		return
+
 	if(ishuman(C))
 		var/mob/living/carbon/human/H = C
 		if(!(H.has_left_hand() || H.has_right_hand()))

code/game/turfs/simulated/floor.dm

@@ -187,7 +187,7 @@ GLOBAL_LIST_INIT(icons_to_ignore_at_floor_init, list("damaged1","damaged2","dama
 	if(T.turf_type == type)
 		return
 	var/obj/item/thing = user.get_inactive_hand()
-	if(!prying_tool_list.Find(thing.tool_behaviour))
+	if(!thing || !prying_tool_list.Find(thing.tool_behaviour))
 		return
 	var/turf/simulated/floor/plating/P = pry_tile(thing, user, TRUE)
 	if(!istype(P))