When Oliver opens the door to the basement, smoke comes through the open door. When Oliver enters the basement itself, there is no smoke at all blowing toward the door emanating from the fire.
When Sarah gets wet in Oliver's car, he blames it on the car's roof. When the car's exterior is shown as they pull away, there is no visible damage to the roof.
After the second fire, the viewer is told that only one side wing of the house remains. But when it is shown again, most of it - including the main wing - is still there.