Understanding the Order of Asynchronous Processing

import UIKit
import AWSCore
import AWSS3
import AWSDynamoDB

class LoadViewController: UIViewController, UINavigationControllerDelegate, UIScrollViewDelegate{


    var loadImages: UIImage = [ ]
    varloadItems: DDBTableRow = [ ]

    var userId—String?
    varuserName —String?
    varpagnatedOutput—AWSDynamoDBPagnifiedOutput?

    @IBOutlet weak var scrollView: UIScrollView!

    let defaults = NSUserDefaults.standardUserDefaults()

    override func viewDidLoad(){
        super.viewDidLoad()

        self.scrollView.delegate=self

        self.userName=defaults.stringForKey("userName")
        self.userId=defaults.stringForKey("userId")


        loadUser()

    }
    override funcdidReceiveMemoryWarning(){
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }


    funcaddImage (image:UIImage)
    {
        let weight = self.scrollView.frame.height
        let width = self.scrollView.frame.width

        loadImages.append(image)
        let myImageView= UIImageView()
        myImageView.frame = CGRectMake (width*CGFloat(loadImages.count-1), 0, width, weight)
        myImageView.image=image
        myImageView.contentMode=.ScaleAspectFit
        scrollView.addSubview(myImageView)
        scrollView.contentSize=CGSizeMake(width*CGFloat(loadImages.count), weight)

    }



    funcloadUser()
    {
        let dynamoDBObjectMapper = AWSDynamoDBObjectMapper.defaultDynamoDBObjectMapper()

        letqueryExpression= AWSDynamoDBQueryExpression()
        queryExpression.hashKeyValues=userId
        queryExpression.scanIndexForward=false
        var loadCounter: Int=0
        dynamoDBObjectMapper.query(DDBTableRow.self, expression:queryExpression).continueWithExecutor(AWSExecutor.mainThreadExecutor(), withBlock:{(task:AWSTask!) ->AnyObject!in
            if(task.error!=nil){
                print("Error:\(task.error)")

            } else{
                if(task.result!=nil){
                    self.pagnifiedOutput=task.result as?AWSDynamoDBPagnifiedOutput

                    US>for item in (self.pagnifiedOutput?.items)!
                    {
                        lettableRow=item as!DDBTableRow

                        print(tableRow.Date)
                        self.downloadImage(tableRow.ImageURL!, loadCounter:loadCounter)
                        self.loadItems.append(tableRow)
                        loadCounter+=1

                    }
                }
                self.performSegueWithIdentifier("unwindToMainSegue", sender:self)
            }
            return nil
        })
    }

    func downloadImage(S3 DownloadKeyName: String, loadCounter:Int) {

        var completionHandler—AWSS3TransferUtilityDownloadCompletionHandlerBlock?

        let queue —dispatch_queue_t =dispatch_queue_create("com.gologo13.gcd", DISPATCH_QUUEUE_SERIAL)

        let expression = AWSS3 TransferUtilityDownloadExpression()
                expression.downloadProgress={(task:AWSS3TransferUtilityTask, bytesSent:Int64, totalBytesSent:Int64, totalBytesExpectedToSend:Int64)in
                    dispatch_async(dispatch_get_main_queue(), {
                        let progress=Float(totalBytesSent)/Float(totalBytesExpectedToSend)
                        NSLog ("Progress is: %f", progress)
                    })
                }


        completionHandler={(task, location, data, error) ->Void in
            dispatch_async(dispatch_get_main_queue(), {
                if(error)!=nil){
                    NSLog ("Failed with error")
                    NSLog("Error: %@", error!)
                }
                else{
                    print(Success)
                    self.addImage(UIImage(data:data!)!)
                    // LoadCounter Debugging
                    print(loadCounter)
                    // LoadCounter does not output values in order
                }
            })
        }

        let transferUtility = AWSS3TransferUtility.defaultS3TransferUtility()

        transferUtility.downloadToURL(nil, bucket:S3BucketName, key:S3DownloadKeyName, expression:expression, completionHander:completionHandler).continueWithBlock{(task)->AnyObject!in
            iflet error=task.error{
                NSLog("Error: %@", error.localizedDescription);
                //  self.statusLabel.text="Failed"
            }
            iflet exception=task.exception{
                NSLog("Exception: %@", exception.description);
                //  self.statusLabel.text="Failed"
            }
            iflet_=task.result{
                //    self.statusLabel.text="Starting Download"
                NSLog("Download Starting!")
                // Something with uploadTask.
            }
            return nil;
        }
    }

}