UITableViewで、下と上にテーブルを引っ張って更新するときのエラー

UITableViewを使って、データのリフレッシュ・ページングをしたいと考えているのですが、
下に引っ張ってリフレッシュするときに
大きく下に引っぱってしまうと、エラーが起きていまいます。

fatal error: Array index out of range

はじめは、リフレッシュを行った時に同時にページング処理も行っているためだと思うのですが、現状エラーを解決することができません。

import Foundation
import UIKit
import Alamofire
import SwiftyJSON

class RequestViewController:UIViewController,UITableViewDataSource,UITableViewDelegate{

    @IBOutlet weak var table: UITableView!


    private var userNameArray: [String]! = []
    private var userImgArray: [String]! = []
    private var userIDArray: [Int]! = []
    private var userIndexArray: [Int]! = []
    private var userImage: String!
    private var dataCount:Int! = 0
    private var loadingCounter:Int! = 0
    private var beforeUserIDArray:Int! = 0


    private let loadNow: UIActivityIndicatorView! = UIActivityIndicatorView(frame: CGRectMake(0, 0, 50, 50))

    var refreshControl:UIRefreshControl! = UIRefreshControl()

    override func viewDidLoad() {
        super.viewDidLoad()
        self.table.backgroundColor = UIColor(white: 0.95, alpha: 1)
        self.getRequest()

        self.refreshControl = UIRefreshControl()
        //self.refreshControl.attributedTitle = NSAttributedString(string: "引っ張って更新")
        self.refreshControl.addTarget(self, action: "refresh", forControlEvents: UIControlEvents.ValueChanged)
        self.table.addSubview(refreshControl)

        //// スクロールする毎にロードする際のインジケーター表示
        self.loadNow.activityIndicatorViewStyle = UIActivityIndicatorViewStyle.Gray
    }

    func refresh()
    {
        print("refresh!!!")
        //取得した配列を開放
        self.userNameArray.removeAll()
        self.userImgArray.removeAll()
        self.userIDArray.removeAll()
        self.userIndexArray.removeAll()

        //loading countの初期化
        self.loadingCounter = 0
        //セルのカウントを初期化
        self.dataCount = 0
        self.getRequest()
    }

    func scrollViewDidEndDecelerating(scrollView: UIScrollView) {
        print("SCROLL")
        if self.table.contentOffset.y >= self.table.contentSize.height - self.table.bounds.size.height {
            print("self.table.contentOffset.y = \(self.table.contentOffset.y)")
            print("self.table.contentSize.height  =\(self.table.contentSize.height)")
            print("self.table.bounds.size.height = \(self.table.bounds.size.height)")

            if self.loadNow.isAnimating() == false {
                print("self.loadNow.isAnimating() == false ")
                print(self.loadingCounter)
                if self.loadingCounter != 0{
                    print("scrollViewDidEndDecelerating ")
                    self.getRequest()
                }
            }
        }
    }

    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        // tableCell の ID で UITableViewCell のインスタンスを生成
        let cell = self.table.dequeueReusableCellWithIdentifier("requestTableCell", forIndexPath: indexPath)

        //選択しても色がつかない状態にする
        cell.selectionStyle = UITableViewCellSelectionStyle.None

        // Tag番号1で UILabel インスタンスの生成
        let content1 = self.table.viewWithTag(-1) as! UILabel
        let content2 = self.table.viewWithTag(-5) as! UILabel

        if cell.viewWithTag(-3) != nil && cell.viewWithTag(-4) != nil{
            var allowButton: UIButton = UIButton()
            allowButton = cell.viewWithTag(-3) as! UIButton
            allowButton.addTarget(self, action: "touchAllowBtn:",forControlEvents: .TouchUpInside)

            var dontAllowButton: UIButton = UIButton()
            dontAllowButton = cell.viewWithTag(-4) as! UIButton
            dontAllowButton.addTarget(self, action: "touchDontAllowBtn:", forControlEvents: .TouchUpInside)

            content1.text = nil
            content1.text = "\(self.userNameArray[indexPath.row])"

            content2.text = nil
            content2.text = "\(self.userIDArray[indexPath.row])"

            self.userImage = self.userImgArray[indexPath.row]
            self.setUserImg(cell, path: indexPath.row)
        }


        return cell
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        if self.dataCount != 0 {
            return self.dataCount
        }
        return 0
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }



    //通知内容読み込み用関数
    func getRequest(){
        print("loading count = \(self.loadingCounter)")
        print("self.refreshControl.refreshing = \(self.refreshControl.refreshing)")
        // ローディングアイコン処理
        self.table.tableFooterView = self.loadNow
        if self.refreshControl.refreshing == false{
            self.loadNow.hidden = false
            self.loadNow.startAnimating()
        }
        Alamofire.request(.GET, Const().URL_API + "/activities/showRequest", parameters: ["my_id": 1 , "loading" :self.loadingCounter])
            .response { request, response, data, error in
                if error == nil {
                    let json = JSON(data: data!)
                    //print("JSON = \(json)")
                    self.dataCount = json["request_data"].count + self.dataCount
                    for var i = 0; i < json["request_data"].count; i++ {
                        if(json["request_data"][i]["user_name"] != nil){
                            self.userNameArray.append(json["request_data"][i]["user_name"].string!)
                        }else{
                            self.userNameArray.append("")
                        }
                        //ユーザーIDを取得するコードを挿入
                        if(json["request_data"][i]["user_id"] != nil){
                            self.userIDArray.append(json["request_data"][i]["user_id"].int!)
                        }else{
                            self.userIDArray.append(0)
                        }

                        if(json["request_data"][i]["user_img_url"] != nil){
                            self.userImgArray.append(json["request_data"][i]["user_img_url"].string!)
                        }else{
                            self.userImgArray.append("no_data")
                        }

                        if(json["request_data"][i]["relation_index"] != nil){
                            self.userIndexArray.append(json["request_data"][i]["relation_index"].int!)
                        }else{
                            self.userIndexArray.append(999)
                        }
                    }
                    self.table.reloadData()
                    //更新が終わったのでグリグリを削除
                    if self.loadNow.isAnimating() == true{
                        self.loadNow.stopAnimating()
                    }
                    if self.refreshControl.refreshing == true{
                        self.refreshControl.endRefreshing()
                    }
                    self.loadingCounter = self.loadingCounter + 1
                }
                else {
                    print("error!")
                }
        }
    }

    //画像処理
    func setUserImg(cell: UITableViewCell, path: Int){
        let userImage: UIImageView = cell.viewWithTag(-2) as! UIImageView
        userImage.backgroundColor = UIColor.lightGrayColor()
        userImage.layer.cornerRadius = 27.5

        userImage.image = nil

        if self.userImage != "no_data" {
            Alamofire.request(.GET, self.userImage)
                .response { request, response, data, error in
                    if error == nil {
                        dispatch_async(dispatch_get_main_queue()) { () in
                            userImage.image = UIImage(data: data!)
                            //colonyImage.addGestureRecognizer(colonyImageTapRecognizer)
                        }
                    }
                    else {
                        print("error!")
                    }
            }
            userImage.layer.masksToBounds = true
        }
        else {
            userImage.image = nil
        } 
     }

    func touchAllowBtn(sender: UIButton) {
        let btn: UIButton! = sender
        let cell: UITableViewCell = btn.superview?.superview as! UITableViewCell
        let index:Int = (self.table.indexPathForCell(cell)?.row)!

        if sender.currentTitle == "allow"{
            print("userIndex = \(self.userIndexArray[index])")
            print("userID = \(self.userIDArray[index])")
        }
    }

    func touchDontAllowBtn(sender: UIButton) {

        let btn: UIButton! = sender
        let cell: UITableViewCell = btn.superview?.superview as! UITableViewCell
        let index:Int! = (self.table.indexPathForCell(cell)?.row)!

        print("ID = \(index)")
        if sender.currentTitle == "dont"{
            print("userID = \(self.userIDArray[index])")

            self.deleteCell(self.userIDArray[index])
        }
     }
}

なにかありましたら、随時補足させていただきますのでよろしくお願い致します。