A zombie who died from a broken neck would be unable to walk or even move. A broken neck with severed spinal cord (the spinal cord must be severed for this sort of injury to be lethal) is effectively the same as if the head is completely severed.
Glen is shown fixing the points on the Winnebago from the front of the RV. The points are only accessible from the inside of the RV, as the points are located in the distributor on the back of the engine.
When Rick and Shane are in the middle of the field where Shane yells at Rick saying, "Right here, right now, you're not even gonna fight for 'em?" there are Emergency units flashing their red, white and blue lights behind Rick's left shoulder.
When Shane puts a gun to Randall's head, his gun clicks like a revolver. He uses a Glock, which is a striker fired gun, it does not use a hammer like a revolver.