The Reds lost for the first time under Freedman as they went down 2-1 in the Championship clash at The Valley.
Frederic Bulot opened the scoring as early as the seventh minute when he found the target with a free kick from 20 yards.
Michail Antonio restored parity for Forest soon after when he cut inside from the left and fired a low shot past Stephen Henderson.
However, Gabon international midfielder Frederic Bulot secured the points for Charlton seven minutes from the half-time interval when he turned in a Lawrie Wilson centre.
The loss was Forest’s first since Freedman took over at the start of last month, but the Scot did not sound too disappointed, which is probably strange.
“To win five games out of six was a momentous effort, and we paid the price for that,” the 40-year-old told Forest’s official website.
“It just caught up with us. I felt we needed a little bit more composure - we had enough of the ball and enough chances.
“The intent was there - great attitude, fantastic support right until the end, we kept on going, huffed and puffed a little bit around their area, but overall I can’t be too disappointed with how the month’s gone.”
Should Nottingham Forest fans be disappointed?
The Championship is a very tough and tricky league, and Forest’s defeat to Charlton at The Valley should not really come as a shock to anyone.
Nevertheless, both the Forest players and the fans should be disappointed with the loss. The Reds had built a nice momentum and looked to be on their way to the playoffs, but then came this setback.
Forest, though, did not play badly at Charlton. The Nottingham-based side created a number of chances in the first half and also came close in the second period.
Freedman’s side ended the game with 55% of the possession, 14 shots of which five were target, and six corners.