A goal down and being pinned back for lengthy periods and the team took the game to the home side in the second half, Arsenal rang the changes and the introduction of Dennis Bergkamp breathed life into their attack.
"We defended so well and it is frustrating to come away with nothing," said Dean afterwards, before admitting that he could not tell for sure if Thierry Henry was offside in making the run that led to the equaliser.
"I've not seen it on TV, but I know how quick Henry is. It looked about ten yards offside at first but I'm not sure - it's just disappointing.
"We did well for the first 20 minutes of the second half and they were getting frustrated. At the same time, we could have been two or three up at half-time and that would have been great for us.
"I'm not being disrespectful, but I think Arsenal had run out of ideas at one stage. Bergkamp made a difference coming off the bench by dropping off the front and had a big impact on the game.
"We got punished because you know they will have a spell in the game when they will punish you."
Dean concluded by saying it will not be long before Helder Postiga finds the net - the young Portuguese striker failed to add to Darren Anderton's early opener after finding himself in the clear twice in the first half.
"Helder worked very hard and has been doing well in training, banging them in. You can't knock him, he was getting into positions and if he keeps doing that it won't be long before he gets his goal."
Dean Richards suspects that Arsenal had run out of ideas at one stage in the second half on Saturday - which made defeat even more difficult to take.