Boss Lee said after the match: "He just gets on with it - it was long time ago that happened, but you are always going to get that," said Lee, "It is part and parcel of football that you get barracked at an old club.
"Andy made a decision to move on, his career has gone on and Norwich have done a lot of good things since then. It perhaps made him more determined and he just got on with it and was not fazed by it."
Lee was impressed most by the penalty save: "I could tell by his body language that Andy was ready to save it. It was a good save, but our players also reacted well to it, making a good second defensive save, if you like, who reacted very quickly."
But Lee did admit: "Did I think he would save it? The truth of that is no. We are pleased with a point, and had to deal with a lot of different systems this afternoon. It was a dogged and determined display.
"It keeps our run going, but we have got Sheffield United on Tuesday and then Southampton, so they are all tough games."
Lee however is fairly annoyed with striker Barry Hayles due to his sending off after he argued with officials.
"I have not asked Barry what he said, I have left it alone, but I will investigate it. I think he implied Darren dived and was talking to Darren about missing the penalty or something.
"I don't know what it was, but I assume it was for a reaction to the decision."
Millwall's next match is a tough test at home on Tuesday night against table-topping side Sheffield Utd.