When you first see the house it looks like there is a tractor by the barn.
Warren's hair changes color. When she picks up a tarp from the ground to shield her from the sun her hair is (Season 4) silver, after she walks for a while and then removes it her hair is (Season 5) black.
When Murphy gets to the drone both doors are open when one had closed when she left.
When they are tilling the field there is a fully tilled field behind them that they are supposed to have done later.