Ravendb tag indexing

gistfile1.cs

using System;
using System.Linq;
using Raven.Client.Client;
using Raven.Client.Indexes;
using Raven.Database.Indexing;

namespace ConsoleApplication2
{
    internal class Program
    {
        public class Image
        {
            public string Name { get; set; }
            public string[] Tags { get; set; }
        }

        private static void Main(string[] args)
        {
            var store = new EmbeddableDocumentStore() {RunInMemory = true};
            store.Initialize();
            using (var session = store.OpenSession())
            {
                session.Store(new Image
                                  {
                                      Name = "First",
                                      Tags =
                                          new[] {"Nice", "Color", "Big"}
                                  });
                session.Store(new Image
                                  {
                                      Name = "Second",
                                      Tags =
                                          new[] {"Nice", "Color"}
                                  });
                session.Store(new Image
                                  {
                                      Name = "Third",
                                      Tags =
                                          new[] {"Solo"}
                                  });
                session.SaveChanges();

                var indexDefinition = new
                    IndexDefinition<Image, Image>()
                                          {
                                              Map = images => from image in images
                                                              from tag in
                                                                  image.Tags
                                                              select
                                                                  new {Tag = tag},
                                          }.ToIndexDefinition(session.Advanced.Conventions);

                indexDefinition.Stores.Add("Tag", FieldStorage.Yes);
                indexDefinition.Indexes.Add("Tag", FieldIndexing.NotAnalyzed);

                session.Advanced.DatabaseCommands.PutIndex("ImagesByTags",
                                                           indexDefinition);

                var queryBigOrNice =
                    session.Advanced.LuceneQuery<Image>("ImagesByTags").WaitForNonStaleResults()
                        .WhereEquals("Tag", "Big")
                        .OrElse()
                        .WhereEquals("Tag", "Nice");

                var queryBig =
                    session.Advanced.LuceneQuery<Image>("ImagesByTags").WaitForNonStaleResults()
                        .WhereEquals("Tag", "Big"); 

                var queryNice =
                    session.Advanced.LuceneQuery<Image>("ImagesByTags").WaitForNonStaleResults()
                        .WhereEquals("Tag", "Nice");

                var querySolo =
                    session.Advanced.LuceneQuery<Image>("ImagesByTags").WaitForNonStaleResults()
                        .WhereEquals("Tag", "Solo");

                var manualQuery =
                    session.Advanced.LuceneQuery<Image>("ImagesByTags").WaitForNonStaleResults()
                    .Where("Tag:Nice or Tag: Big");

                var resultBigOrNice = queryBigOrNice.ToArray();
                var resultBig = queryBig.ToArray();
                var resultNice = queryNice.ToArray();
                var resultManual = manualQuery.ToArray();
                var resultSolo = querySolo.ToArray();

                Assert.AreEqual(2, resultManual.Length); 
                Assert.AreEqual(1, resultBig.Length);    
                Assert.AreEqual(2, resultNice.Length);   
                Assert.AreEqual(2, resultBigOrNice.Length); 
                Assert.AreEqual(1, resultSolo.Length);      
            }
        }

        public static class Assert
        {
            public static void AreEqual(int i, int j)
            {
                if (i != j)
                {
                    throw new Exception(string.Format("i != j : {0},{1} ", i, j));
                }
            }
        }
    }
}

To be honest my intuition seems to suggest it should fail too but I can't put my finger on why. At the moment Ayende has suggested the Authorization bundle as the solution for the problem I currently have (assign 'audiences' to 'content' such that a user only sees content for which they are in the audience.) I was going to use tags to accomplish and this is something Authorization includes already.