Directorial Blunders

When the developers constructed the Shinra helicopter
piloted by Reno during the opening sequence, they reused 
the textures for the lettering on the side of the helicopter.

As a consequence, the lettering appears reversed on one side
of the helicopter. This is especially noticeable since they reversed
the texture for the Shinra logo, which appears correctly
on both sides of the chopper. 

The same sign appears on both sides of the street in Edge.

Bahamut destroys some construction debris with one
of his fireball attacks.

However, moments afterward when Cloud shows up,
the exact same debris is back as though nothing had happened.