Why is Raycast hitting player?

I made a roblox raycast script and ti damages the person holding the tool even though it is blacklisted. What did I do wrong?

local gun = script.Parent
local fireEvent = gun.FireEvent
local FastCast = require(gun.FastCastRedux)
local firePoint = gun.Handle.FirePoint

local bulletsFolder = workspace:FindFirstChild("BulletFolder") or Instance.new("Folder", workspace)
bulletsFolder.Name = "BulletFolder"

local bulletsTemplate = Instance.new("Part")
bulletsTemplate.Anchored = true
bulletsTemplate.CanCollide = false
bulletsTemplate.Shape = "Ball"
bulletsTemplate.Size = Vector3.new(1, 1, 1)
bulletsTemplate.Material = Enum.Material.Metal

FastCast.VisualizeCasts = false

local caster = FastCast.new()

local castParams = RaycastParams.new()
local castParams = RaycastParams.new()

castParams.FilterType = Enum.RaycastFilterType.Blacklist

castParams.IgnoreWater = true
castParams.FilterDescendantsInstances = {gun.Parent, bulletsFolder, bulletsTemplate, gun}

local castBehavior = FastCast.newBehavior()
castBehavior.RayCastParams = castParams
castBehavior.Acceleration = Vector3.new(0, -workspace.Gravity, 0)
castBehavior.AutoIgnoreContainer = false
castBehavior.CosmeticBulletContainer = bulletsFolder
castBehavior.CosmeticBulletTemplate = bulletsTemplate

local function onEquipped()
    castParams.FilterDescendantsInstances = {gun.Parent:FindFirstChildWhichIsA("Part") , bulletsFolder, bulletsTemplate, gun}
end

local function onLengthChanged(cast, lastPoint, direction, length, velocity, bullet)
    if bullet then
        local bulletLength = bullet.Size.Z/2
        local offset = CFrame.new(0, 0, -(length - bulletLength))
        bullet.CFrame = CFrame.lookAt(lastPoint, lastPoint + direction):ToWorldSpace(offset)
    end
end

local function onRayHit(cast, result, velocity, bullet)
    local hit = result.Instance

    local character = hit:FindFirstAncestorWhichIsA("Model")

    if character and character:FindFirstChild("Humanoid") then
        if not character:FindFirstChild("Gun") then
            character.Humanoid:TakeDamage(25)
        end
        if hit.Parent ~= gun.Parent and hit.Parent ~= gun then
            print(hit.Parent)
        elseif hit.Parent == gun.Parent or hit.Parent == gun then
            warn(hit.Parent, "shot themself due to a bug...")
        end
    end

    game:GetService("Debris"):AddItem(bullet, 5)
end

local function fire(player, mousePosition)
    local origin = firePoint.WorldPosition
    local direction = (mousePosition - origin).Unit
    local velocity = 69426969

    caster:Fire(origin, direction, velocity, castBehavior)
    gun.Handle.GunShot.Playing = true

end

fireEvent.OnServerEvent:Connect(fire)

gun.Equipped:Connect(onEquipped)

caster.LengthChanged:Connect(onLengthChanged)
caster.RayHit:Connect(onRayHit)

here's the script