Actually, my retcon for Nathan's press conference is slightly different from yours.

In my version, Nathan announces that he has the ability to fly and then, knowing the unbelievable nature of such a statement he starts to demonstrate it. As he attempts it though, he discovers that his powers have vanished (and ditto for Peter and the PsiCop) possibly as a result of being in the room as Peter nuked the virus container.

The version also makes the title of the episode, "Powerless," make a bit mroe sense.