The Walking Dead

After Rick subdues Morgan who has attacked him, he tries to help Morgan remember who he is by saying that Morgan found him "last year" in Rick's front yard. Although the story's chronology is not synchronized with the series' calendar timeline, surely it has been more a year since Rick last saw Morgan.

*Actually, it is more likely to be slightly less than a year since Rick last saw Morgan. As Judith's parentage is questioned, we can assume that Lori became pregnant around the time Rick found her and Carl. (Again assuming she stopped sleeping with Shane once Rick returned.) Lori gave birth prematurely to Judith, so she would have been pregnant for less than 38 weeks. It also does not appear to have been more than 3 months since Lori's death (considering Judith's growth/development.) So unless Rick wandered for some months before meeting up with Glenn in Atlanta, it would have been nearly a year since Rick last saw Morgan.

Goof: At 40:49 Michonne is wearing a crossbow on her back. When the camera angle changes, the crossbow is already in the car as she is shutting the hatch.

Sarah Wayne Callies is listed in the opening credits of this episode.

The weapon that Rick uses in this episode is the M4 carbine.

Although listed in the main and guest credits respectively, both Lori (Sarah Wayne Callies) and Carol (Melissa McBride) do not appear in the episode (obviously).

As a tribute to the fallen in this episode, no music is played during the closing credits.

Dallas Roberts who plays Milton (the Governor's advisor) in this episode also starred in another AMC television series, Rubicon. Dallas played a genius-level analyst in a New York City federal intelligence agency.

Although credited in the main and guest credits, Andrew Lincoln (Rick), Sarah Wayne Callies (Lori), Norman Reedus (Daryl), Steven Yuen (Glenn), Lauren Cohan (Maggie), Chandler Riggs (Carl), Melissa McBride (Carol) and Scott Wilson (Hershel) do not appear in this episode.

This episode also marks the first appearance of Michael Rooker (Merle) and David Morrissey (The Governor) in the main credits.

As stated in the episode, the song that Beth and Maggie sing is called "The Parting Glass". It is a traditional song from Ireland and Scotland that has existed since at least the early 1600's and is sung at the end of gatherings.

Goof: the front (& likely rear) tire on Daryl's bike changes from a dirt bike tire (when on the farm) to a street tire (outside of the farm)

The Public Works that Shane and Rick bring Randall to exist in the fictional Mert County, Georgia. In reality, the site is in Griffen, Spalding County, Georgia.

From the opening scene, most of the Atlanta survivors stayed down at the barn. But when Glenn, Rick and Shane followed Herschel up to his house, there was no one down at the barn but the dead Walkers. The next scene showing the barn had them all down their again.

After the opening credits, the scene opens up with a shot of a windmill. The windmill is from the Aermotor Company that sells windmills like that to pump water out of the ground.

The total number of Walkers in Herschel's barn was 15: twelve neighbors, two of Herschel's relations and Sophia.

During the scene where Maggie is being attacked by the Walker and Glenn comes to the rescue, keep an eye outside. You will see a man handling the horses outside the store.

As Daryl hallucinates talking to his brother, the dirt on Daryl's face changes position from shot to shot.

The Cherokee Rose primary time to bloom is in the early spring with bright green leaves. However, the flower is capable of blossoming in the fall under good conditions. Given the condition of the plant Daryl finds, the timeframe of the show is set in the fall.

If you look at the banners behind Shane and Otis in the gym, you will see that the school they are at has the initials C.H.S. and has a Cougar as a mascot. In reality, the school used for these scenes is Newnan High School (NHS) that does have the Cougar as their mascot.

Goof (though possible explanation): The suicide that ended up as a Walker had its legs eaten at by other zombies. It's made clear in the series that the zombies only eat the living and not the dead. He had time to produce a noose, get up a tree and jump so there shouldn't have been any Walkers nearby while he died.
It's possible the camper was chased up the tree by walkers or walkers caught up to him by the time he was ready to hang himself, so once he jumped the walkers would've started eating away at him, and likely stopped when the body lost the scent that attracts walkers - body heat/etc - likely why he wasn't pulled down - by the time his legs where eaten the body finally read/smelled dead to the walkers and they abandoned it.

T-Dog's real name is revealed to be "Theodore Douglas."