Why is the dialog "Oops! Sorry!" still showing for me but not for Ben in the lesson?

package com.teamtreehouse.stormy;

import android.app.AlertDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.content.Context;
import android.os.Bundle;


public class AlertDialogFragment extends DialogFragment {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        Context context = getActivity();
        AlertDialog.Builder builder = new AlertDialog.Builder(context)
                .setTitle(context.getString(R.string.error_title)) //change all the text messages to String resources. Steps: 1. Alt+Enter. 2. give the resource a name 3. then hit ESC key when CONTEXT is highlighted in red.
                .setMessage(context.getString(R.string.error_message))
                .setPositiveButton(context.getString(R.string.error_ok_button_text), null);

    AlertDialog dialog  = builder.create();
        return dialog;
    }
}

package com.teamtreehouse.stormy;

import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;

import com.squareup.okhttp.Call;
import com.squareup.okhttp.Callback;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.Response;

import java.io.IOException;


public class MainActivity extends ActionBarActivity {

    public static final String TAG = MainActivity.class.getSimpleName();

    //create new method to check for network connectivity

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        String apiKey = "d5faf0cb201f103df4dde0b8b0a4f490";
        double latitude = 37.8267;
        double longitude = -122.423;
        String forecastUrl = "https://api.forecast.io/forecast/" + apiKey +
                "/" + latitude + "/" + "," + longitude;

        if (isNetworkAvailable()) {  // [**]   //create new method to check for network connectivity and wrap requesting HTTP in it.
            OkHttpClient client = new OkHttpClient();
            Request request = new Request.Builder().url(forecastUrl).build();

            Call call = client.newCall(request);
            call.enqueue(new Callback() {
                @Override
                public void onFailure(Request request, IOException e) {

                }

                @Override
                public void onResponse(Response response) throws IOException {
                    try {
                        Log.v(TAG, response.body().string());
                        if (response.isSuccessful()) {
                        } else {
                            alertUserAboutError();
                        }
                    } catch (IOException e) {
                        Log.e(TAG, "Exception caught: ", e);
                    }
                }
            });
        }
            else { //[***if network unavailable]
                Toast.makeText(this, getString(R.string.network_unavailable_message), Toast.LENGTH_LONG).show(); //extract String resource from "Network is unavailable!"
        }

        Log.d(TAG, "Main UI code is running!");
    }

    private boolean isNetworkAvailable() { // We'll set a return value based on the network availability. [**]
        //We are going to use an Android Class called ConnectivityManager
        ConnectivityManager manager = (ConnectivityManager)
                getSystemService(Context.CONNECTIVITY_SERVICE);

        //  now we need to substantiate a NetworkInfo object. Lets call it 'networkInfo'
        NetworkInfo networkInfo = manager.getActiveNetworkInfo(); //now we can analyze the network info to see if it is both present and active
        // ^ to use .getActiveNetworkInfo method, we need to add another permission to manifest*

        boolean isAvailable = false;    //initialize boolean variable = is network present: true or false // Let's set it to false initially and then we'll only set it to true if the network is actually available.
        if (networkInfo != null && networkInfo.isConnected()) { // check the network using an 'if' statement //if ("network is not null" aka network is present AND network is connected to the web)
            isAvailable = true; //[**]
        }
        return isAvailable; //now we have a condition that will check if the network is presented and connected!!!!
        // But what if this returns false?
        // We should let the user know that the network is unavailable.
        // Then they can check their network status, disable airplane mode. [***]
    }
    private void alertUserAboutError() {
        AlertDialogFragment dialog = new AlertDialogFragment();
        dialog.show(getFragmentManager(), "error_dialog");
    }
}