No Cowher could not have reviewed that. You can't review an incomplete pass, you can review to reverse a call TO incomplete but you can't review FROM incomplete. Especially because the refs blew the whistle and stopped play before anybody recovered (though it clearly would have been recovered by a Steeler since the only Seahawk within 15 yards had just been knocked on his butt).
I know just seeing if your on your toes. Not sure if that was a fumble or not, I was outside during that play.