Sword System | Client-Server security help

[RobloxJrTrainer (Rblxjrtrainer)]

Hey all. I have this Sword system I made with various security actions, but I am having some trouble with making a certain action happen on the server, like a critical hit; based on the current animation that is playing.
The issue is, can’t exploiters play an animation that triggers this critical hit, Since I am using animator:GetPlayingAnimationTracks()?

Server Script part:

-- ValidateSwordHit function
validateSwordHit.OnServerInvoke = function(player, eHums, currentCombo)
	print(currentCombo)
	if typeof(player) ~= "Instance" then
		return false
	end

	local char = player.Character or player.CharacterAdded:Wait()
	local hum = char:WaitForChild("Humanoid")
	local animator = hum:WaitForChild("Animator") :: Animator
	local currentTime = tick()

	playerHitTimes[player] = playerHitTimes[player] or 0

	local timeSinceLastHit = currentTime - playerHitTimes[player]
	playerHitTimes[player] = currentTime

	if timeSinceLastHit < 0.25 then
		warn("Time since last hit is too soon.")
		return false
	end
	
	-- TODO: Track combo on the server separately to reject any impossible combos

	local aliveHums = {}
	for _, eHum in ipairs(eHums) do
		if typeof(eHum) ~= "Instance" or not eHum.Parent:IsDescendantOf(workspace) then
			return false
		end

		-- If everything above passes; add a distance check
		local eChar = eHum.Parent
		local distance = (eChar.PrimaryPart.Position - char.PrimaryPart.Position).Magnitude
		if distance >= serverProperties.MAX_LEGAL_HIT_RANGE then
			warn("Distance is invalid/impossible")
			return false
		end
		if eHum.Health > 0 then
			table.insert(aliveHums, eHum)
		end
	end

	-- All security checks pass; apply damage and server only logic
	local appliedStun
	for _, aliveHum in ipairs(aliveHums) do
		if aliveHum.Health > 0 and aliveHum.Parent ~= char and not char:GetAttribute("Stunned") then
			-- First apply a stun to the player that IS attacking
			-- TODO: apply a half stun to the player attacking
			
			local dmg = serverProperties.BASE_DAMAGE

			-- For normal attacks
			local isCritical = rng:NextNumber(0, 1) <= serverProperties.CRITICAL_HIT_CHANCE
			if isCritical then
				dmg = setCriticalHitDmg(dmg)
			end
			
			-- TODO: Replace with a more secure critical hit method
			for _, track in pairs(animator:GetPlayingAnimationTracks()) do			
				if track.Animation.AnimationId == sharedProperties.Tracks[4] then
					isCritical = true
					dmg = setCriticalHitDmg(dmg)
					break
				end
			end

			-- Deduct damage if attacking multiple enemies at once
			local damageDeduction
			if #aliveHums >= 2 then
				damageDeduction = 1 - (#aliveHums * 0.1)

				damageDeduction = math.max(damageDeduction, 0.5)
			else
				damageDeduction = 1
			end

			dmg *= damageDeduction

			-- Final Damage
			local finalDmg = math.round(dmg)
			local didAttack, msg = utilityModule.attack(aliveHum.Parent, char, finalDmg, serverProperties.ENEMY_STUN_DURATION, stunModule)
			faceAttacker(char, aliveHum.Parent)
			
			if didAttack then
				-- Apply attack logic
				local isFinalBlow = aliveHum.Health <= 0

				-- Apply a hit reaction to the enemy
				local preloadedTracks = preloadedAnimations[aliveHum.Parent] -- stored on the character of the player/npc
				if not preloadedTracks then
					warn("[DEBUG]: Did not find a preloaded track for ", aliveHum.Parent, " possibly R15?")
					return false
				end

				local hitReactionTrack = preloadedTracks[currentCombo]
				if not hitReactionTrack then
					warn("[DEBUG]: Did not find a hitReactionTrack for ", aliveHum.Parent)
					return false
				end

				local playedHitTrack = fxManager.playOrStopTrack(hitReactionTrack, true)
				playedHitTrack.Ended:Connect(function()
					playedHitTrack:Destroy()
				end)

				swordEffectEvent:FireAllClients(player, aliveHum, isCritical, isFinalBlow)
			else
				warn(msg)
			end
		else
			continue
		end
	end

	return true
end

Here is the client script:

local function onSwordActivate()
	if swordCooldown then
		return
	end
	-- return if the player is stunned
	if char:GetAttribute("Stunned") then
		return
	end

	swordCooldown = true

	-- Update combo
	local newCombo = updateCombo()

	lastSwingTime = tick()

	-- Create and play the specified track
	local currentTrack = animations[currentCombo]
	local track = fxManager.playOrStopTrack(currentTrack, true) :: AnimationTrack
	if not track then
		warn("Did not successfully play track")
		swordCooldown = false
		return
	end

	local validateSuccess = false
	track.KeyframeReached:Connect(function(keyName)
		if keyName ~= "Slash" then
			return
		end

		-- Play a swing sound
		swordSwingSound:FireServer(sword.Handle) -- fire an event to play a sword swing sound

		local newHitbox = createHitbox()

		newHitbox.OnTouch = function(eHums)
			for _, eHum in ipairs(eHums) do
				if eHum == hum or eHum.Health <= 0 then
					continue
				end
			end
			
			validateSuccess = validateSwordHit:InvokeServer(eHums, currentCombo)
			if not validateSuccess then
				warn("Did not successfully validate hit!")
			end
		end

		newHitbox:Start()

		task.wait(0.05)
		newHitbox:Stop()

		newHitbox:Destroy()
	end)

	track.Stopped:Connect(function()
		swordCooldown = false
		track:Destroy()
	end)
end

The issue is these parts on the server:

-- TODO: Replace with a more secure critical hit method
			for _, track in pairs(animator:GetPlayingAnimationTracks()) do			
				if track.Animation.AnimationId == sharedProperties.Tracks[4] then
					isCritical = true
					dmg = setCriticalHitDmg(dmg)
					break
				end
			end

Any help would be appreciated.