C# dictionary ordering

DictionaryOrderTest.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace DictionaryOrderTest
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Testing without deletions or extra insertions: ");
            Console.WriteLine(Test(false, false) ? "Passed" : "Failed");
            
            Console.Write("Testing with deletions and no extra insertions: ");
            Console.WriteLine(Test(true, false) ? "Passed" : "Failed");
            
            Console.Write("Testing with deletions and extra insertions: ");
            Console.WriteLine(Test(true, true) ? "Passed" : "Failed");

            Console.Write("Testing without deletions and with extra insertions: ");
            Console.WriteLine(Test(false, true) ? "Passed" : "Failed");

            Console.ReadKey();
        }

        static bool Test(bool doDelete, bool doInsert)
        {
            var dict = new Dictionary<string, object>();
            var list = new List<string>();

            var rand = new Random();
            for (var i = 0; i < 1000000; i++)
            {
                var key = rand.Next().ToString();
                try
                {
                    dict.Add(key, null);
                    list.Add(key);
                }
                catch (ArgumentException)
                { i--; }
            }

            if (doDelete)
            {
                dict.Remove(dict.Keys.First());
                list.Remove(list.First());
            }

            if (doInsert)
            {
                dict.Add("Another", null);
                list.Add("Another");
            }

            var idx = 0;
            foreach (var pair in dict)
                if (pair.Key != list[idx++])
                    return false;
            return true;
        }
    }
}

stdout

Testing without deletions or extra insertions: Passed
Testing with deletions and no extra insertions: Passed
Testing with deletions and extra insertions: Failed
Testing without deletions and with extra insertions: Passed