I've edited my post, they had a great start to the season, winning 4, drawing 2 and losing 2 of their first 8 games, to see them 5th. They only won 1 of the remaining 30 games.
Your memory doesn't serve you correctly. In the only season Millwall have ever been relegated from the top flight (89-90 season) they were 15th on Christmas day. They finished bottom and 17 points from safety so they spent a lot more than just the last 10 mins of the season in the relegation...