Behe wrote
"One last charge must be met: Orr maintains that the theory of intelligent design is not falsifiable. He's wrong. To falsify design theory a scientist need only experimentally demonstrate that a bacterial flagellum, or any other comparably complex system, could arise by natural selection. If that happened I would conclude that neither flagella nor any system of similar or lesser complexity had to have been designed. In short, biochemical design would be neatly disproved. "
This is untrue. One can still show that there is a evolutionary pathway and still have a 'designer'. If Behe's argument were to hold then we can now safely conclude that "intelligent design" has been disproven since it has been shown that "a comparable complex system" could have arisen by natural selection.
Did Behe just disprove Intelligent Design ?
But Behe does not stop there, he continues:
"Let's turn the tables on Orr. Is natural selection falsifiable? He writes, "We have no guarantee that we can reconstruct the history of a biochemical pathway. But even if we can't, its irreducible complexity cannot count against its gradual evolution. . . ." This is a dangerously antiscientific attitude. In effect he is saying, "I just know that phenomenally complex biochemical systems arose gradually by natural selection, but don't ask me how." With such an outlook, Orr runs the risk of clinging to ideas that are forever insulated from contact with the outside world. "
Note that Orr's answer does not address falsifiability, merely Behe's presumption that if we cannot reconstruct every single pathway, that this counts against gradual evolution. In fact Behe already stated that showing one pathway is enough to destroy Intelligent Design arguments.
It is very anti-scientific to state that since we do not know how something happened this is evidence of Intelligent Design, rather than our own ignorance.