The truth is that you don't need IAOFM to come to the conclusion that Fox is blaming play calling for the 3rd & 7 call. Just read Woody's article, it tells you everything.
Fox is not necessarily blaming the run call itself, but that the run call was totally telegraphed by the personnel. Everyone in the stadium and at home watching knew it was a run call, so obviously the Ravens could figure it out.
That is what Fox is saying, that he would have liked to at least disguise it enough to open up the possibility of a pass. He said the personnel grouping was such that Peyton couldn't have called an audible to something else if he wanted to, and the Ravens knew it.
This also tells me that Fox does not control the play calling anywhere near as much as some fans think. I think McCoy may be even more conservative than Fox, if you can believe that.