When seen briefly being dragged away, Lionel appears to be clean shaven, while in Phantom, he had a small scruffy beard.
As the water breaches the dam, it swells upward like a wave. Once past the structures on either side, the water would simply spread out and push onward rather than move upward since there's no containment to cause it to do so.
In the under water scene of Lex trapped in the police cruiser the dome lights are flashing. The electrical system would have been shorted out under water, the dome lights could not have worked.