When Rick, Carl and Hershel wait for the lone Walker to pass after escaping the farm, there is no rear window in their car. But, after regrouping with the other survivors, there is a rear window.
When firing on the walkers outside of his home, Hershel fires a shotgun over a dozen times without having to stop and reload. Shotguns generally only hold between seven and nine shells fully loaded.
When the truck stops after Lori threatens to jump you can clearly see that the shots inside show there is a turning just behind the truck. However the long shot of it turning round has them on a straight road with no turnings.
When Daryl returns to the farm to get Carol, you can see his motorcycle has 'offroad' tires, especially noticeable by the large MTX style tread pattern on the front wheel.
In later scenes, on the highway meeting point and when they pull over when Rick runs out of gas, he suddenly has 'road' tires with a significantly different tread pattern.
When everyone leaves the farm, they flee in different directions as fast as their vehicles can carry them. They drive most of the night like this, each eventually decides to turn back then all of them end up back at the same place--the traffic snarl--at the same time the next day.
When Hershel is reloading his shotgun, a walker approaches him from behind. Suddenly, Rick shows up and shoots the walker just behind Hershel's head. Firing a gun from that close to someones ears should make him/her unable of hearing anything at least for a few minutes. But immediately after that, Hershel hears and answers Rick's question easily.
Approximately two minutes into the episode, when the Walkers are migrating at the wooden fence, a man shouts, "Action!"
While Rick, Hershel and Carl drive away from the attacked farm, Hershel is still watching his occupied farm from the car's back window. Doing so, he should easily notice Andrea running toward the car while they were escaping the farm.
Whilst firing the shotgun Herschel isn't being affected by the recoil.
When the herd breaks through the fence at about 3 minutes in, one of the lead female walkers' cardigan starts to fall off and she shrugs it back on. A walker wouldn't care about their clothing.