David tells Katie she can tell where north is by feeling the moss on trees. The truth is moss grows anywhere it is moist and shady, which is not always the north side.
Around 26mins into the episode David has transformed into the 'Hulk' and he's curious about the crashed object/meteor, the Hulk throws a small tree to the left, you can clearly see a rope/line attached to the tree, which is obviously used to pull it away.
The meteor is shown entering the Earth's atmosphere and moving in a south-easterly direction over India toward Australia but it is then shown landing in Utah, which would require a substantial change in direction.