Just about everything - for the Falcons that is. They did every possible thing wrong that a team can do. While the Packers played very well, they had help from the Falcons to win the game, and lots of it. After a winning season, a 1st place post season seed, the Falcons come out of the playoffs beaten down by the Packers to the tune of 48 to 21.
The Falcons had the week bye and some people will put the loss on the fact that they were "rusty." That's just not the case. Any team that gets to the playoffs is not going to be rusty if they have the first week bye. They aren't sitting at home on the sofa watching ESPN for 2 weeks. They do their normal routine to prepare for the game, in the off week and the week of the game. Rust is not an issue. What is an issue, is a team that comes into a game and doesn't play the game that got them there and they let the other team dictate how things are going to go. That's exactly what the Falcons did.
Things started out well enough. A nice touchdown drive off of a Packers fumble. A great punt return run back by Weems. Things were looking okay at that point. Then, the whole thing went downhill from there. Mistake after mistake made. The fact that the Falcons couldn't get the offense back on the field for long stretches. The fact that the Falcons secondary looked like the secondary of last year - bad, atrocious even. The space they gave the Packers receivers was just about criminal. Aaron Rogers had players in space to throw to and he did it over and over again. Then, that very secondary committing penalty after penalty giving the Packers free yards. When the Falcons did get on offense, they decided to fumble the ball. Not once but several times. As I've heard Michael Irvin say, "You can't put the church's money on the ground." The Falcons poured the money on the ground. Matt Ryan threw 2 picks. He was sacked 5 times. He made only 29 pass attempts and Michael Turner was held to 39 yards rushing. You cannot win that way - against any team - and certainly not against an offense like Aaron Rogers commands.
The Falcons had their best season since 1998. They did all the right things during the season. They looked poised to make a deep playoff run maybe even a trip to the Super Bowl, but they didn't do the things that got them to the post season in the first place. They gave the Packers the game and the Packers took it and ran with it and passed with it and won with it. Maybe next year Falcons fans.