I mean, in my view that was clearly a touchdown. But if the call on the field is that he stepped out with THE FOOT THAT WOULD HAVE MADE IT A LEGAL CATCH, I don't see how "the call stands" and keeping it a catch makes any sense.
And come on... You're gonna say that the official was all over the whistle in the 3 yards between the catch and the end zone?
I don't get it.