In the initial shots of the walker being pulled out of the well, it is shown rising up the middle, not touching the sides of the well, as would happen if the rope were still hung over the pipe across the top of the well. However, when the walker reaches the top of the well, it is being pulled over the edge, so it should have been dragging against the side on the way up the inside of the well.
When the group is pulling the walker out of the well, the end of the rope is attached to the horse's saddle, and yet the whole group is still straining to pull it out. The horse could easily pull the walker out simply by walking the other way.
As Glenn is being lowered into the well we see a shot of the group letting the rope out slowly. The rope between Shane and the pump is slack. If Glenn were at the end of the rope between Shane and Glenn would be very tight. The same occurs as they pull him out.
The premise of getting the walker out of the well is invalid and pointless. Once the water is contaminated with any kind of disease vector it would be considered unsafe to drink.
When they were pulling the walker out of the well, the walker's jeans were not wet or soaked, but they should be from being in a well full of water.
Jane McNeill, who plays Patricia, after being consoled by Shane, begins to laugh while looking away. Possibly due to the face she makes while nodding.
In the previous episode Rick is seen pulling his colt python from its holster and handing it to Otis, who tells him its a fine weapon and he'll bring it back... but in this episode at around the 1.5 minute mark Rick is shown sitting down next to Carls bed and the colt python is there in his holster.