Continuity mistake: Near the start, the camera pans out to see the dome now covered in a layer of black. Outside of the dome you can see nice green fields, a small forest area, little houses and everything looks rosy. However a few episodes back the military launched a MOAB (mother of all bombs) and and the surrounding area was wiped out completely.
Continuity mistake: When Junior attempts to find a way out in the cement factory tunnels, he is angered at the fact the dome has cut clean through the factory as well. A few seconds later, Junior turns to the Dome and takes his hood off and yells at the dome. In the next frame with Junior, his hood is back up and he begins punching at the dome, his hood is then removed again.